6:11 "It's never too early to start coding".. I've been telling my 3 year old kid that but she insists on learning how to read first... Kids these days..
i am starting to think im better than the average programmer after watching this. might be a sampling bias since better programmers dont leave the house.
lol I cringed hard when I saw the first girl using "+=" with a string in Python (since strings are immutable in Python, it basically creates a new string every time making the complexity O(N^2)).
@@mohitsagar9492 if im not wrong string concatenation are ammortized O(1) just like push_back() in C++ without reserve(). either way, it should be a non issue nowadays. there were more... pressing mistakes.. in the video.
@@stxnw Right in C++ strings are mutable! However in Python and Java they are immutable. Honestly everyone other than the first girl and that one Indian dude with Hashmaps didn't seem to be actual programmers so I didn't expect much from them anyway XD. And you will be surprised how much these small optimizations can matter when dealing with massive data!
The guy at the end said “I think it’s an essential skill everyone should have.” I cannot agree more. I’ve discounted myself for years as dumb or not learned because I’ve never delved into things like this which have always put me in awe and today I realized, when time applied, I could actually do this if I wanted to, and how far progressed would we be technologically if everyone had this under their belt from a young age xD
I'm a 3rd-year Computer Engineering student and this video makes me wanna refresh my knowledge in programming (both C and C++). Love from the Philippines.
I nervously watched and attempted the problems being a recent Computer Science graduate (thinking that I wouldn't know and would feel stupid). I learned that I can at least answer simple coding problems! Thanks 4 years of college!
Yeah but, you spent 4 years and $40,000+ to learn what anybody can learn for free on TH-cam in a couple months. And in another 4 years, everything you did learn will be obsolete, but you'll still be paying for it.
@@nickfleming3719 instate public college + athletic scholarships + academic scholarships + college isn’t really all about what you learn in your courses + computer science isn’t just being good a programming + L + ur white
@@nickfleming3719 imagine watching a few “how to code” vids on TH-cam and then feeling superior enough to make fun of someone for getting a BS in computer science
I watched this video for the first time a year ago. I had no idea what they were even talking about. Now a year later, i know exactly whats going on and im able to solve pretty much every problem. It feels nice to see progress.
Dude I watched this like 6 months ago and didn't know how they did any of this but after taking a CS class in Python I understand it now. Thats insane...
Remember doing my final exam for Cobal on punch cards. Program was due before the 2 hour final (2 week assignment). The final exam, he took all our programs, and dropped them on the floor and told us to reassemble our program.
The funny thing about 0:52 is that her solution of using reversed() is actually far more efficient than manually writing out a function to reverse the string since Python library functions are highly optimized.
@@meelaud2103 But thats not a right mindset to be a programmer with, especially in today's market. What looks like cheating to you is just another tuesday for us. It just works like that, as said "You dont need to reinvent the wheel everytime you need to go somewhere with your car".
@@bronzejourney5784 She wasn't the one making up the rules. And honestly, there is a lot to be learned by trying to accomplish something in as many different ways as possible, rather than calling it good with the "easy" or "correct" way.
An idea: After each question you show the optimal solution and why is it optimal. I interviewed like dozens of programmers and one thing to learn as an interviewer - help the programmer to know what mistake he/she made. We don't want to keep people doing the same errors over and over again. This is counterproductive for the industry.
Yeah for the last one, I thought the solution would just be to use a double for loop and an if statement to find the sum of all the combinations and then just return whatever is at those indexes
5:40 He has some typos and syntax errors but the overall concept is great. It makes a dict map of "which remainder maps to the current number". And as soon as it encounters that remainder as a unique number, the dict returns the complementary number that sums with it. Good job coming up with that on the spot.
That's quite interesting, first of it kind that i have seen.... But you or the person solving it should always walk through the code so that we will learn too
It's always important to make sure the answerer knows how it works, or at least gives an answer that, if the written code doesn't quite do it, does justify the thought process, and checks out.
5:40 He has some typos and syntax errors but the overall concept is great. It makes a dict map of "which remainder maps to the current number". And as soon as it encounters that remainder as a unique number, the dict returns the complementary number that sums with it. Good job coming up with that on the spot.
would've have been more interesting, if you asked them to just walk it through instead of writing code. This way you can find people who have no clue of coding but have natural design/engineering skills. This would also require you to re-arrange the question for better understanding. Cool :D
That's kinda hard if you don't really understand the basic ruleset that programming provides (ways data/variables are stored, and ways to compare them). But I also think it would be a really good idea.
if you don't know anything about coding and the language they cannot test for anything imho obv. analogy here but would a racecardriver prove his talent if he hasn't touched go-karts at a young age. I have been good at math all my life, went up to AP Calc/Passed, but first time I saw a for loop iteration I was astounded, maybe makes it easier to understand after you have seen it but most of coding algos and components making them are kind of like magic tricks, you will need practice (alot) to understand how they are done. My .02
@@WoWkiddymage But that's the point, everyone does coding. Everyone who has learned how to manually calculate the root of a given number is pretty much primed to code in their heads, programming is just an abstraction layer to offload strict calculations while the programmer conceptualizes the steps. And yeah, definitely a dope idea, anything to get people involved who didn't think they were suited for it. Maybe some kind of paid bootcamp next where people just get money for learning a basic curriculum, that'd be fun too.
@@minhuang8848 What I'm saying is that these algorithm-based questions are created with restraints that you only understand if you have programmed before. Yes, coding/programming is "just" an abstraction but that is often the difficult part about it. Putting these concepts into the limits of programming data structures and being restricted by time complexities. I think the general idea of pattern recognition/problem solving that is similar to the coding question would create a cool sort of puzzle, but then that would be a totally different type of analysis of the problem if you don't include the ruleset that programming provides. You would basically have to teach someone all the basics of programming to see if they understand how to fit a problem into the constraints that programming provides.
Also, I'm not saying it wouldn't be a good idea. I think it would be really cool to tickle people's brains on the subject. I just think that the implementation of this kind of "social experiment" would be quite difficult, it would cost a lot of effort on the participants not previously understanding the limitations. Who knows though, there might be some cool ways to implement this idea...
programming languages are easy to learn but becoming a professional developer is not. so I think it's not ok to say everyone "come on start to learning programming".
I’ve written a 12,000-line Python thingy that works and solves a massive problem. I have no idea how to approach most of that in the video. Not sure why there’s such a focus on math and data stuff. You don’t need to know the mega-geeky stuff to be useful.
That first girl solution was nice, I been around your channel around the past but this is the first time seeing you do these videos. It's been a while since I solve some problems, these videos awake that feeling in me again.😁
I would never thought of using a hashmap and exceptions to solve the last one. All that was needed was two pointers, one starting in the beginning and the other at the end, keep checking the sum and move the appropriate pointer if the sum if bigger or smaller than the target.
@@АлександрСоколов-т2я I think the leetcode one times you out if you use the naive approach, if he the guy in the video had done it on leetcode he probably remembers doing it that way because that's a way that will get your answer validated
@@flavorlessquark8614 yep and since its the first code on leetcode I think the average coders might have already solved it since when they teach DSA in courses they try combination sum as the first question to solve usually
@@Vikas_Kumar_Singh I would like to think that most coders, as mysef, are self thaught. It's also a thing to solve it, as it is another to solve it efficiently
First time I watched this video was before I started coding and I had no idea what's happening. I just returned to see how far I've come. It's unbelievable how far I've come in 5 months
One day I’ll be a coder and work at a big data company and reply to this video that I made it! Thanks for all this information time to get started on my journey! 💪
To the first girl, who solved the reverse string problem : Nick just forbade you to use inbuilt functions, not inbuilt operators. Simply - string[::-1]
Hmm, just off the top of my hat I can mention 20 programming languages: Basic, Fortran, Algol60, Algol68, PL/I, Pascal, Lisp, APL, Cobol, Prolog, C, C++. C#, Ada, Java, Javascript, Rust, Julia, Ruby, Python. I guess I'm getting old.
-- sum2d in Haskell with standard Prelude function 'foldl' : sum2d = foldl (foldl (+)) 0 -- outputting the sample result: main = putStr $ show $ sum2d [[1, 2, 3],[4, 5]]
I thought the First guy - Indian guy would solve the Difficult round first...but SAVE by the SECOND Indian guy! WAY TO GO INDIAN TEACHERS on TH-cam!!!!
@@NoOne-sy5fg I think with a hashmap the problem can be solved in O(N) even if the array isn't sorted. If the array is sorted then you can get O(N) using a more basic method, but I don't think the problem statement specified that the array was necessarily sorted. The hashmap is definitely more complicated in terms of basic operations that would need to be understood, but in code it is all abstracted away and then using the hashmap will end up with cleaner code than the other method that has the same time complexity but only works on a more constrained problem.
its cool to see that so many people are actually getting in to coding. But still I cant stop myself thinking the whole time: "But that's a one liner?!" xD
@@johndorian4078 took the exam already. It was kind of hard, but not that bad. Honestly, I was more following along for fun than actually preparing for the exam.
if youre interested in a better way for the reversed string (in python): def reverse(st): result = '' for index in range(len(st)): result += st[-(index + 1)] return result all you do is use the regressive index (iterable_variable[-value]) in python to sum each respective character in a loop.
As a cs student who did a year in industry last year, learning programming can get you a whole lot more than $100. (But a little extra cash is always appreciated, especially for just a few minutes of your time!)
Super interesting watching people solve this stuff. Every question I was like “oh yeah just do this” then they come up with something completely different. $200 dollar guy threw me right off
He found an O(n) solution, iterating over the array exactly three times to determine a solution if any exist, when the naïve solution is O(n^2), using nested loops. I didn’t see the hashmap solution lol. He deserves the $200.
@@JordanMetroidManiac He had the right idea with the subtraction and then finding the other value within the remainder of the array, not sure why he overcomplicated it by using the hashmap as his first attempt. Interesting to see regardless.
@@RandomVideos-yz5qf That's a O(N^2) solution though since you need two for loops. The way he did it (storing using a dictionary), you can do it in a single loop O(N) solution.
When you have imposter syndrome, think of the robot guy from Grandma's Boy and laugh about that character lol. You're doing great, keep it up and code everyday.
6:09 "Start coding early. It's never too early to start coding." Actually, just start coding. It's never too late to start coding either. I'm a photographer in my 40's and I try to learn a new programming or scripting language every year. I'm on my 9th language now.
@@wiljagerhardt1219 I'm going to agree with this comment, what's the most years you've spent on a single language? While learning a lot of languages may be fun, it's much more useful to be skilled in 2 or 3 than mediocre in 9. Get good with a functional language and an OO language.
@@wiljagerhardt1219 That's an interesting assumption. Entirely false but interesting nonetheless. I can only conclude that the assumption stems from one's own experiences. However, when I choose to learn something, no matter what it is, I fully immerse myself (8+ hours per day, 5 to 6 days per week) for the duration of the time I choose to learn it. And I don't stop learning about said topic when that duration is concluded. I just reduce the amount of time I spend working with said subject to make room for my next endeavor. This doesn't only apply to coding, this also applies to everything I do in life: coding, network engineering, automotive mechanics, dancing, art, photography, video production, cooking, etc. I realize this seems like an unrealistic approach to you but that's the difference between people like me and people who are not like me. I also realize some people just aren't capable of doing something like this but for me it's just a simple matter of what level of commitment I am willing to put into something and sticking to it. Have a nice day.
@@ragtop63 just because you dedicate yourself for a period of time to learning a language doesn't mean you are NOT mediocre, it takes years to become even decent at programming and you need to either create projects or have professional experience. So you saying you are on your 9th language is just silly to be honest, I work with very very smart people who have spent years programming and they are fluent in maybe 4 max. You might know the basics but if someone give you a repo and asked you to understand it you would be lost
In most modern languages, the simplest answer is the same. You could write it in C and you've already covered C++, C#, and others. There my be some difference in syntax, but the algorithm is the same.
or if you want to allow duplicate elements (like sum=8 and more than one 4 to appear in the list) a multiset. Yes, that's basically a hash map with the values being the counts.
The C# programmer was cut out of the video in the twosum equals 9 problem, cause Kenny gave him the prize instantly the moment he saw Foreach written in the whiteboard.
I wanna agree with that fella at the end, programming is an essential skill. People use the skills needed for programming all the time already. But learning programming languages, efficiently writing algorithms, learning how to best store information, etc, all of these surprisingly make thinking and processing information easier for me. I don't know how to explain it. Which brings up a good side point, I SUCK at explaining things. But thinking about things in a programming sense helps with that too.
You also need the skill of plumbing every day to take a shit on your toilet, or the skill of an electrician, to give power to your computer. Today everyones flying, do you also need to know the basics of operating an airbus or boeing airliner? You wear clothes everyday... why don't you learn how to sew and manufacture shoes, pants, jackets? Life's short, people are into different things. Not everyone want's to learn how to code, or how hardware works. Most people don't even understand, how a car motor runs, or how we breath with our lungs in detail. Do you know, how to help a woman giving birth? This should be an essential skill in my opinion. Nothing's more essential, than the creation of a new human beeing.
@@PySnekDude, chill out. Programming is a more valuable work than making clothes just from the fact that its used in more than 100 careers for various stuff. If you don't like it, don't learn. But denying it's importance shows how immature you are 😂
id love to see someone answer using matlab, most of these r 1 liners "doesn't matter what language" Matlab: 1. string{1}(end:-1:1) 2. sum(Arr,[],'all') 3. (bit longer) [x = array of ints, t = target] for i1 = 1:numel(x) i2 = find(x + x(i1) == t) if(i2) break end end
I've been learning Python for three weeks and saw this video...thought I'd give the Two Sum a shot. number_array = [1, 3, 5, 6, 11, 23] result = 9 for number in number_array: count = 0 result_found = False while count < len(number_array): if number + number_array[count] == result: print(f"The result is {number} and {number_array[count]}.") quit() count += 1
Here's my solution: nums = [1, 3, 5, 6, 11, 23] result = 9 for i in range(len(nums)): result_found = False for j in range(len(nums)): if nums[i] + nums[j] == result: print('The result is ', nums[i], 'and', nums[j]) if result_found: break
For added challange and practice, implement an algorithm which runs in 1) O(n) time and O(n) additional space, 2) O(n log n) time and O(1) additional space but is allowed to modify input array. --- spoilers below --- def find_two_sum(total, numbers): num_set = set(numbers) for num in numbers: if total - num in num_set: return num, total - num raise ValueError() def find_two_sum(total, numbers): numbers.sort() front = 0 end = len(numbers) - 1 while front < end: a, b = numbers[front], numbers[end] if a + b == total: return a, b elif a + b < total: front += 1 else: end -= 1 raise ValueError()
@@littricks3631, it expresses how runtime or memory size of the algorithm grows in relation to the size of the problem. See en.wikipedia.org/wiki/Big_O_notation
The one with the array is kinda easy... Python: array = [1, 2, 3, 4, 5, 2, 331] sum = 0 for i in array: sum += i print(sum) only 5 lines of code. Why would you ever use java???
4:17 problem. The 4:50 solution is O(n) But there's an O(log(n)): • Sort array using quicksort. • Create two integers to store the left and right indices to sum (l and r). • while l < r: Sum a[l] and a[r]. If equal to the valué we looking for, return true. Else If greater then r--; else l++;
@@kNowFixx You are right. I made a mistake when writing the initial comment, the algorithm described is O(log n) not O(n log n). I will edit my message to correct it. Thank you very much for your appreciation 😊
In JS to last one: function twoSum(array, sum){ const args = [] for(let i = 0; i < array.length; i++){ array.forEach(e=>{ if(sum == e + array[i]) args.push([e, array[i]]) }) } return args } That function return each possibly combination of two number in array that sum the "sum" variable
I would answer this question like a true data scientist. Using matrix multiplication: for the matrix A you could consider the quadratic form e⊤Ae, where e is the column vector whose entries are all 1's.
the way i thought of doing the twosum question after you explained it was to have two for loops (like a nested loop) so the outer loop will pick one number at a time from the array and then with the inner one you check the sum with every other element except itself to see if you can get the sum and if sumarray==sum then you can easily print the numbers because you already have their indexes from the for loop can be implemented in any popular language of course taking the sum and subtracting each element and then checking for the difference in the array was an interesting approach to me very cool video :) subbed
in this case, the array is sorted. so you don't actually need to double loop through every element in the array. as long as the sum is bigger than the target sum, you can skip the 2nd level loop
So the thing is, the solution you thought of definitely works, and it's even the first solution most people would think of. But the problem with it is that it doesn't scale well. If you have an array with a million elements, then you'll need to do a million comparisons and that's just for the first element. On the second one you will do a million - 1 comparisons and so on and so forth. It's perfectly acceptable with a small input but when the array becomes very large running it this way becomes very time consuming, as opposed to the hash map method where you only need to do, at most, a million operations in this example since you only iterate over the array once. This is an entire topic called "Time Complexity" and it's quite important to keep in mind if your use case requires super efficient code.
For the last question that's how I'd solve the problem (level 0 coding) : A=np.array([1,3,5,6,11,23]) size=len(A) for i in range (size): for j in range(i+1,size): test=A[i]+A[j] if test==9: nb=test print("the numbers are in index",i,"and",j)
@@computerprogrammer7942 The guy's solution is actually better, it has a time complexity of just O(n) using the hashmap method. The nested for loop approach is also known as the naive approach and it has a time complexity of O(n^2)
The funny thing about C is that the "sum of a matrix" problem can just be done like for(int i = 0; i < length; i++) sum += matrix[i]; since matrices are almost the exact same as 1d arrays
a real programmer won’t go outside
based
based
based
based
I'll rune the joke
Also your right
6:11 "It's never too early to start coding"..
I've been telling my 3 year old kid that but she insists on learning how to read first... Kids these days..
hahaha
so lazy…
Lol
Yea like really they should stop being lazy. I had already graduated by the time I was 3.
You kinda need to read first in order to understand coding :P
(and yes I know this is most likely a joke lel)
i am starting to think im better than the average programmer after watching this. might be a sampling bias since better programmers dont leave the house.
they fear to the sun
just want everybody to know that i am all green on my github
lol I cringed hard when I saw the first girl using "+=" with a string in Python (since strings are immutable in Python, it basically creates a new string every time making the complexity O(N^2)).
@@mohitsagar9492 if im not wrong string concatenation are ammortized O(1) just like push_back() in C++ without reserve(). either way, it should be a non issue nowadays. there were more... pressing mistakes.. in the video.
@@stxnw Right in C++ strings are mutable! However in Python and Java they are immutable. Honestly everyone other than the first girl and that one Indian dude with Hashmaps didn't seem to be actual programmers so I didn't expect much from them anyway XD. And you will be surprised how much these small optimizations can matter when dealing with massive data!
The guy at the end said
“I think it’s an essential skill everyone should have.”
I cannot agree more.
I’ve discounted myself for years as dumb or not learned because I’ve never delved into things like this which have always put me in awe and today I realized, when time applied, I could actually do this if I wanted to, and how far progressed would we be technologically if everyone had this under their belt from a young age xD
Issue is not everyone enjoys it
So is math yet so many people hate it with passion regardless of their potential.
I feel the same way about boards. Everyone should at least skateboard, surf, Onewheel, etc. Progress toward peace and no hunger, imagine it xD
bruh nothing is hard if you apply yourself. Its just memorizing things. Like advanced maths. Just some people dont care to learn
@@mtutoriales I think it mostly depends on the teacher. It's also because of the reputation that maths has as "the hard subject".
I'm a 3rd-year Computer Engineering student and this video makes me wanna refresh my knowledge in programming (both C and C++). Love from the Philippines.
"In java it doesnt work"
Man rethought his existence in .5 second 🤣🤣
Hahaha "Why am I here, What purpose do I have"
Hey! 🤣
i did this in java in 5 mins
In Java it would be easy for me to do it however I don’t knw any other programming language yet
I know python the easiest one
I nervously watched and attempted the problems being a recent Computer Science graduate (thinking that I wouldn't know and would feel stupid). I learned that I can at least answer simple coding problems! Thanks 4 years of college!
Yeah but, you spent 4 years and $40,000+ to learn what anybody can learn for free on TH-cam in a couple months.
And in another 4 years, everything you did learn will be obsolete, but you'll still be paying for it.
@@nickfleming3719 instate public college + athletic scholarships + academic scholarships + college isn’t really all about what you learn in your courses + computer science isn’t just being good a programming + L + ur white
@@nickfleming3719 Computer Science is not about programming or been a programmer
@@elephantwaffle5612 ok I see why you needed it
@@nickfleming3719 imagine watching a few “how to code” vids on TH-cam and then feeling superior enough to make fun of someone for getting a BS in computer science
When grandpa comes out swinging like, "binary, assembly, matlab, basic, that's what I used to use when I was a kid"
cosmic rays
Cobol, fortran
Matlab is still used by Engineers
@@essaquadry true and mathematics
@@sodiboo butterflies
I watched this video for the first time a year ago. I had no idea what they were even talking about. Now a year later, i know exactly whats going on and im able to solve pretty much every problem. It feels nice to see progress.
I want to do so
same here
Woah for real? What helped you achieve that
same here! i'm on day 20 of angela yu's 100 days of code on udemy, and i was able to solve every question in the video 😁
@@filyboy7I am also studying that course 😊
Dude I watched this like 6 months ago and didn't know how they did any of this but after taking a CS class in Python I understand it now. Thats insane...
in what U toke it
same here,that hits different
@@momenmohamed8337 in a intro to CS college class
If a online class drop the link
@@vanci2039 th-cam.com/video/JP7ITIXGpHk/w-d-xo.html
"What language do you program in?"
Old guy: Punch cards
Lmao
Remember doing my final exam for Cobal on punch cards. Program was due before the 2 hour final (2 week assignment). The final exam, he took all our programs, and dropped them on the floor and told us to reassemble our program.
I'm crying😭😭😭🤣🤣🤣🤣🤣
@@ingiford175 EEP！
🤣
after finishing a course in python programing, i feel prepared to write my print('hello world')
💪🏿
YES.
Indeed
After taking an advanced python course, i feel prepared to write:
def main():
print("hello world")
if __name__ == "__main__":
main()
Same here
i think we might be giving money to people that don't really need it...
Or even the coders in this youtube channel
I'm ok with that.
I say try it on kids
I thinks homeless person should learn programming
@@Thunder-dp7du right? lol
The funny thing about 0:52 is that her solution of using reversed() is actually far more efficient than manually writing out a function to reverse the string since Python library functions are highly optimized.
no shit XDDD thats y she couldnt use it
You're right, Since Python is written in C, the library functions are super fast.
@@meelaud2103 But thats not a right mindset to be a programmer with, especially in today's market. What looks like cheating to you is just another tuesday for us. It just works like that, as said "You dont need to reinvent the wheel everytime you need to go somewhere with your car".
Recursivity always calling the function + char of the current position until the length of the string would work well too
@@bronzejourney5784 She wasn't the one making up the rules. And honestly, there is a lot to be learned by trying to accomplish something in as many different ways as possible, rather than calling it good with the "easy" or "correct" way.
Q: name 4 programming languages.
Guy at 3:45
A: java (0), python (1), javascript (2), c (3), ruby (4)
hehe 😂
I am guy at 3:45, I approve hahaha
An idea: After each question you show the optimal solution and why is it optimal.
I interviewed like dozens of programmers and one thing to learn as an interviewer - help the programmer to know what mistake he/she made. We don't want to keep people doing the same errors over and over again. This is counterproductive for the industry.
Yeah for the last one, I thought the solution would just be to use a double for loop and an if statement to find the sum of all the combinations and then just return whatever is at those indexes
I feel that way too, but you're asking people on the spot in the street. Without an ide I can't weed out the syntax errors.
@@arkesh110 double for loop is too slow you can do it using 1 and having a set to keep track of the elements you found already
5:40 He has some typos and syntax errors but the overall concept is great. It makes a dict map of "which remainder maps to the current number". And as soon as it encounters that remainder as a unique number, the dict returns the complementary number that sums with it. Good job coming up with that on the spot.
@@MyAmazingUsername shut up. You're just rehashing what I said with a positive spin.
3:37 didn't know "C+" was a programming language 🤔
It came around the same time as C Flat.
The son of c++ is c+😀😀😀😀😀😀
Lol that’s me! I panicked
Family with C hashtag
Maybe he designed it himself, you can never be sure
man at 3:37 is like : C , C# ,C+,C++,C+++,C x max pro ,C lite
Lmaoo
😂😂
Don't forget C- and C-- !
Let's go baby math major :D
And this dude is like take this 20 and get out of here
for reversing a string simply use slicing
string="Ali"
print(string[::-1])
That's what i was thinking
5:20 this challenge can be solve just by using 2 indexes and a for loop to scan the array 1 time since it's ordered
You can do it with one index as well
2:06 Does it matter what language?
Nah
*Processed to write machine code in 0s and 1s*
Wish I was there, literally free money for every single question.
Next time
Literally man 😂😂😂
seriously bro way to easy ques
Yeah literally 10 kyu on CodeWars
skillshare is a scam beware search the topic in yt u'd know btw i teach python and c too in hindi.
That's quite interesting, first of it kind that i have seen.... But you or the person solving it should always walk through the code so that we will learn too
Yesn’t
It's always important to make sure the answerer knows how it works, or at least gives an answer that, if the written code doesn't quite do it, does justify the thought process, and checks out.
5:40 He has some typos and syntax errors but the overall concept is great. It makes a dict map of "which remainder maps to the current number". And as soon as it encounters that remainder as a unique number, the dict returns the complementary number that sums with it. Good job coming up with that on the spot.
Honestly, he overcomplicated that. He had the right idea but then went rogue with the syntax and that code is definitely not maintainable. lol
grandpa still remembers Fortran 💀 3:25
would've have been more interesting, if you asked them to just walk it through instead of writing code. This way you can find people who have no clue of coding but have natural design/engineering skills. This would also require you to re-arrange the question for better understanding. Cool :D
That's kinda hard if you don't really understand the basic ruleset that programming provides (ways data/variables are stored, and ways to compare them). But I also think it would be a really good idea.
if you don't know anything about coding and the language they cannot test for anything imho obv. analogy here but would a racecardriver prove his talent if he hasn't touched go-karts at a young age. I have been good at math all my life, went up to AP Calc/Passed, but first time I saw a for loop iteration I was astounded, maybe makes it easier to understand after you have seen it but most of coding algos and components making them are kind of like magic tricks, you will need practice (alot) to understand how they are done. My .02
@@WoWkiddymage But that's the point, everyone does coding. Everyone who has learned how to manually calculate the root of a given number is pretty much primed to code in their heads, programming is just an abstraction layer to offload strict calculations while the programmer conceptualizes the steps. And yeah, definitely a dope idea, anything to get people involved who didn't think they were suited for it. Maybe some kind of paid bootcamp next where people just get money for learning a basic curriculum, that'd be fun too.
@@minhuang8848 What I'm saying is that these algorithm-based questions are created with restraints that you only understand if you have programmed before. Yes, coding/programming is "just" an abstraction but that is often the difficult part about it. Putting these concepts into the limits of programming data structures and being restricted by time complexities. I think the general idea of pattern recognition/problem solving that is similar to the coding question would create a cool sort of puzzle, but then that would be a totally different type of analysis of the problem if you don't include the ruleset that programming provides. You would basically have to teach someone all the basics of programming to see if they understand how to fit a problem into the constraints that programming provides.
Also, I'm not saying it wouldn't be a good idea. I think it would be really cool to tickle people's brains on the subject. I just think that the implementation of this kind of "social experiment" would be quite difficult, it would cost a lot of effort on the participants not previously understanding the limitations. Who knows though, there might be some cool ways to implement this idea...
this's a great video , at least you motivate some people to learn coding and don't see coding is a impossible mission. Great video , keep going
programming languages are easy to learn but becoming a professional developer is not.
so I think it's not ok to say everyone "come on start to learning programming".
5:35 my nigga even doin the exception handling
Reverse string:
lambda str: str[::-1]
2d array sum:
lambda arr: np.sum(np.array(arr))
I’ve written a 12,000-line Python thingy that works and solves a massive problem. I have no idea how to approach most of that in the video. Not sure why there’s such a focus on math and data stuff. You don’t need to know the mega-geeky stuff to be useful.
27 years old nd just started to code, i love it btw
That first girl solution was nice, I been around your channel around the past but this is the first time seeing you do these videos. It's been a while since I solve some problems, these videos awake that feeling in me again.😁
I would never thought of using a hashmap and exceptions to solve the last one.
All that was needed was two pointers, one starting in the beginning and the other at the end, keep checking the sum and move the appropriate pointer if the sum if bigger or smaller than the target.
it can be done only on sorted array so complexity is O(nlogn). Using hashmap u have O(n) but also same memory complexity
@@АлександрСоколов-т2я I think the leetcode one times you out if you use the naive approach, if he the guy in the video had done it on leetcode he probably remembers doing it that way because that's a way that will get your answer validated
@@flavorlessquark8614 yep and since its the first code on leetcode I think the average coders might have already solved it since when they teach DSA in courses they try combination sum as the first question to solve usually
@@Vikas_Kumar_Singh I would like to think that most coders, as mysef, are self thaught. It's also a thing to solve it, as it is another to solve it efficiently
The array is sorted?
First time I watched this video was before I started coding and I had no idea what's happening. I just returned to see how far I've come. It's unbelievable how far I've come in 5 months
One day I’ll be a coder and work at a big data company and reply to this video that I made it! Thanks for all this information time to get started on my journey! 💪
@Mino Royale fr, to me i'm learning things really quick, might be because i have great willingness to learn.
how goes the journey fellow dev?
How is your journey going
@@Zeeshan_Tanwri ChatGPT has made me somewhat an expert. Thank you for checking in. Hope everyone's coding journey is going well :))
This is something that should be encouraged more. Why would someone dislike this video is beyond my comprehension.
To the first girl, who solved the reverse string problem : Nick just forbade you to use inbuilt functions, not inbuilt operators.
Simply - string[::-1]
It is more of a solving the problem mathematically with basic tools rather than how much do you know about the language itself.
op bro . i also thought the same
Literally posted a comment about that before seeing this one lol
I immediately yelled “LIST COMPREHENSION”
noice.
You can optimize the very first code by just doing this in python:
*string = str(input("Input Your String: "))*
*print(string[::-1])*
return input(“your string: “)[::-1]
input() already returns a string, no need to turn it into a string again
Hmm, just off the top of my hat I can mention 20 programming languages: Basic, Fortran, Algol60, Algol68, PL/I, Pascal, Lisp, APL, Cobol, Prolog, C, C++. C#, Ada, Java, Javascript, Rust, Julia, Ruby, Python. I guess I'm getting old.
-- sum2d in Haskell with standard Prelude function 'foldl' :
sum2d = foldl (foldl (+)) 0
-- outputting the sample result:
main = putStr $ show $ sum2d [[1, 2, 3],[4, 5]]
2:20 hey heeeeeeeeeey lmao
This coding videos are awesome! I don't get impressed by much but this is very fun and interesting. Love it. Can't wait to see the next one of this.
competitive programmers:
“are you insulating our traditions?”
The ultimate indian friend group 4:46 this would be talked about in the friend group for weeks if you can slove it in front of them.
THE GOLDEN RULE of coding; if you stuck in a question, just throw a hashmap to it. 90% of the time you'll make at least some progress...
I thought the First guy - Indian guy would solve the Difficult round first...but SAVE by the SECOND Indian guy! WAY TO GO INDIAN TEACHERS on TH-cam!!!!
The hashmap guy was making things complex for himself...when it could be solved so simple in O(N) time complexity
@@NoOne-sy5fg lol idd, I facepalmed when I heard hashmap.
@@NoOne-sy5fg I think with a hashmap the problem can be solved in O(N) even if the array isn't sorted. If the array is sorted then you can get O(N) using a more basic method, but I don't think the problem statement specified that the array was necessarily sorted. The hashmap is definitely more complicated in terms of basic operations that would need to be understood, but in code it is all abstracted away and then using the hashmap will end up with cleaner code than the other method that has the same time complexity but only works on a more constrained problem.
hard part is the complexity or constraints on input data . Thats what makes u apply mathematics
Q1-
#reversing a string in 2 lines
inputstr=input("Enter the string here")
print(inputstr[::-1])
#imaprogrammerandneedtotelleveryone
What language is that ? I never saw " ::- " operator wow
@@Mariiius53 python and using slicing
echo implode('',array_reverse(str_split($string)));
Real programmers make it in brainfuck
if there's anything i learned from my astronomy degree, it's that everything can be solved with for loops.
"C, C#, C+, C++", can't believe he got away with that
its cool to see that so many people are actually getting in to coding. But still I cant stop myself thinking the whole time: "But that's a one liner?!" xD
Time pressure 🥲
Make sure to check out Nick's video for part 2! th-cam.com/video/WDuZ_S_9vLg/w-d-xo.html
I have a CS exam today, and I'm practicing for the coding problems by going through and doing each problem in Java. Thanks for this video!
if these problems are your practice............................... good luck.
@@johndorian4078 took the exam already. It was kind of hard, but not that bad. Honestly, I was more following along for fun than actually preparing for the exam.
if youre interested in a better way for the reversed string (in python):
def reverse(st):
result = ''
for index in range(len(st)):
result += st[-(index + 1)]
return result
all you do is use the regressive index (iterable_variable[-value]) in python to sum each respective character in a loop.
or even better str = str[::-1]
@LambdaSan Bruh, that's what I was thinking. All these people defining function for a simple task.
3:37 We all just gonna pretend that C+ is a programming language?
After c++: c+++, c++++, c+++++...
Before c++: c+, c, c-, c--, c---, c----...🤣
It's great work done by you and for those who are starting career in IT.
The first 1,000 people to use this link will get a 1 month free trial of Skillshare! skl.sh/kennygunderman07211
Can't even get it for the lack of card
@@7heMech exactly
Thank u very much
Kind hearted man!
☺️
Ok
As a cs student who did a year in industry last year, learning programming can get you a whole lot more than $100.
(But a little extra cash is always appreciated, especially for just a few minutes of your time!)
The two sum could be done iterating 0
if only the questions in the test were this simple
Super interesting watching people solve this stuff. Every question I was like “oh yeah just do this” then they come up with something completely different.
$200 dollar guy threw me right off
He found an O(n) solution, iterating over the array exactly three times to determine a solution if any exist, when the naïve solution is O(n^2), using nested loops. I didn’t see the hashmap solution lol. He deserves the $200.
But he made a small mistake. In Python list object doesn't have any attribute called length, len(arr) would have been correct instead
@@quasii7 Yeah. He had the right idea though and definitely could have debugged it given the chance.
@@JordanMetroidManiac He had the right idea with the subtraction and then finding the other value within the remainder of the array, not sure why he overcomplicated it by using the hashmap as his first attempt. Interesting to see regardless.
@@RandomVideos-yz5qf That's a O(N^2) solution though since you need two for loops. The way he did it (storing using a dictionary), you can do it in a single loop O(N) solution.
All of them were pretty easy. Thank you. I still have some imposter syndrome and this helped.
When you have imposter syndrome, think of the robot guy from Grandma's Boy and laugh about that character lol. You're doing great, keep it up and code everyday.
This is my week 4 of CS and I'm alr stressing that I don't understand any of these lol
@@datcate9116 I am in my first hour of CS and I dont understand any of this
@@billr5842 I'm no longer in CS HAHA
i like the dude who added error handling, catching errors so they don't hit the ground. epic
100$ for reversing a string 🤣 man I worked on a full fledged website for around 1.5 moths for a hackathon that didn't even pay me that much
Awesome idea for a video!
You should make it series I'm sure its gonna give you tons of views
keep up the good work
wow, u went from 30k to almost 80k subs! amazing, didn't realize how much ur channel grew recently
Bro the one kid that goes, “EY” when he says Java doesn’t count 😂
Thanks for creating problems to solve and saving a Street Programmer out in the wild.
Them old dude isn’t messing about .. cobol , fortran 😂
6:09 "Start coding early. It's never too early to start coding."
Actually, just start coding. It's never too late to start coding either. I'm a photographer in my 40's and I try to learn a new programming or scripting language every year. I'm on my 9th language now.
9th one but with 10% knowledge each
@@wiljagerhardt1219 I'm going to agree with this comment, what's the most years you've spent on a single language? While learning a lot of languages may be fun, it's much more useful to be skilled in 2 or 3 than mediocre in 9. Get good with a functional language and an OO language.
@@wiljagerhardt1219 That's an interesting assumption. Entirely false but interesting nonetheless. I can only conclude that the assumption stems from one's own experiences. However, when I choose to learn something, no matter what it is, I fully immerse myself (8+ hours per day, 5 to 6 days per week) for the duration of the time I choose to learn it. And I don't stop learning about said topic when that duration is concluded. I just reduce the amount of time I spend working with said subject to make room for my next endeavor. This doesn't only apply to coding, this also applies to everything I do in life: coding, network engineering, automotive mechanics, dancing, art, photography, video production, cooking, etc.
I realize this seems like an unrealistic approach to you but that's the difference between people like me and people who are not like me. I also realize some people just aren't capable of doing something like this but for me it's just a simple matter of what level of commitment I am willing to put into something and sticking to it.
Have a nice day.
@@KingBobbito Unfortunately Wilja, in my case, would be wrong. But I can see why people would be afraid to move beyond their apprehensions.
@@ragtop63 just because you dedicate yourself for a period of time to learning a language doesn't mean you are NOT mediocre, it takes years to become even decent at programming and you need to either create projects or have professional experience. So you saying you are on your 9th language is just silly to be honest, I work with very very smart people who have spent years programming and they are fluent in maybe 4 max. You might know the basics but if someone give you a repo and asked you to understand it you would be lost
Remember y'all, of you ever get stuck on an interview question, throw a hash map at it
you should zoom even for a second on the code, each time so we can have a look at it.
In most modern languages, the simplest answer is the same. You could write it in C and you've already covered C++, C#, and others. There my be some difference in syntax, but the algorithm is the same.
The 2sum guy is my hero, the man hand writes error handling into it for no reason ❤️
Sponsored by Skillshare, Udemy getting all the PROMOTION is just hilarious. Thanks Skillshare LOL 😂
4:48 If you have no idea what youre doing, always throw a hash map at it - a wise old programmer once
He should have used a (hash)set.
or if you want to allow duplicate elements (like sum=8 and more than one 4 to appear in the list) a multiset. Yes, that's basically a hash map with the values being the counts.
The C# programmer was cut out of the video in the twosum equals 9 problem, cause Kenny gave him the prize instantly the moment he saw Foreach written in the whiteboard.
Yep, it's foreach has worse performance than regular for loops. No need to let people see that solution and start considering it a good approach.
@@sneak9407 I garantee you that the whiteboard would not have enough RAM for any of both approaches
@@sonikblade lmao.
I'm 18 and I've been studying programming for 1 year at the university without any practice and I solved those problems easily)
Find the numbers in the array that sums up a given number? You can pick two random numbers in the array inside a while loop.
I wanna agree with that fella at the end, programming is an essential skill. People use the skills needed for programming all the time already. But learning programming languages, efficiently writing algorithms, learning how to best store information, etc, all of these surprisingly make thinking and processing information easier for me. I don't know how to explain it.
Which brings up a good side point, I SUCK at explaining things. But thinking about things in a programming sense helps with that too.
You also need the skill of plumbing every day to take a shit on your toilet, or the skill of an electrician, to give power to your computer. Today everyones flying, do you also need to know the basics of operating an airbus or boeing airliner? You wear clothes everyday... why don't you learn how to sew and manufacture shoes, pants, jackets? Life's short, people are into different things. Not everyone want's to learn how to code, or how hardware works.
Most people don't even understand, how a car motor runs, or how we breath with our lungs in detail.
Do you know, how to help a woman giving birth? This should be an essential skill in my opinion. Nothing's more essential, than the creation of a new human beeing.
@user-hq4cj6rw7b "Programming is an essential skill".
"CAN YOU FLY AN AIRBUS HUHH"
@@PySnekDude, chill out. Programming is a more valuable work than making clothes just from the fact that its used in more than 100 careers for various stuff. If you don't like it, don't learn. But denying it's importance shows how immature you are 😂
That was insanely entertaining and funny. Please do this again.
The $200 guy had a way more clever solution than I would have
Same it kinda threw me off tbh
id love to see someone answer using matlab, most of these r 1 liners
"doesn't matter what language"
Matlab:
1. string{1}(end:-1:1)
2. sum(Arr,[],'all')
3. (bit longer) [x = array of ints, t = target]
for i1 = 1:numel(x)
i2 = find(x + x(i1) == t)
if(i2)
break
end
end
Respect to everyone who tried and solved it
Keep this kind of videos coming man.
Very inspiring
Cool! Make more of these type of videos!
I've been learning Python for three weeks and saw this video...thought I'd give the Two Sum a shot.
number_array = [1, 3, 5, 6, 11, 23]
result = 9
for number in number_array:
count = 0
result_found = False
while count < len(number_array):
if number + number_array[count] == result:
print(f"The result is {number} and {number_array[count]}.")
quit()
count += 1
nice work!
Here's my solution:
nums = [1, 3, 5, 6, 11, 23]
result = 9
for i in range(len(nums)):
result_found = False
for j in range(len(nums)):
if nums[i] + nums[j] == result:
print('The result is ', nums[i], 'and', nums[j])
if result_found:
break
For added challange and practice, implement an algorithm which runs in
1) O(n) time and O(n) additional space,
2) O(n log n) time and O(1) additional space but is allowed to modify input array.
--- spoilers below ---
def find_two_sum(total, numbers):
num_set = set(numbers)
for num in numbers:
if total - num in num_set:
return num, total - num
raise ValueError()
def find_two_sum(total, numbers):
numbers.sort()
front = 0
end = len(numbers) - 1
while front < end:
a, b = numbers[front], numbers[end]
if a + b == total:
return a, b
elif a + b < total:
front += 1
else:
end -= 1
raise ValueError()
@@mina86 what on earth is this o(n) shit?I have been seeing a lot about this.
@@littricks3631, it expresses how runtime or memory size of the algorithm grows in relation to the size of the problem. See en.wikipedia.org/wiki/Big_O_notation
The one with the array is kinda easy...
Python:
array = [1, 2, 3, 4, 5, 2, 331]
sum = 0
for i in array:
sum += i
print(sum)
only 5 lines of code.
Why would you ever use java???
4:17 problem. The 4:50 solution is O(n)
But there's an O(log(n)):
• Sort array using quicksort.
• Create two integers to store the left and right indices to sum (l and r).
• while l < r: Sum a[l] and a[r]. If equal to the valué we looking for, return true. Else If greater then r--; else l++;
O(n) is better than O(n log(n)), just so you know
@@kNowFixx You are right. I made a mistake when writing the initial comment, the algorithm described is O(log n) not O(n log n). I will edit my message to correct it. Thank you very much for your appreciation 😊
3:00 - that dude is prolly the producer
awesome video, I want more programming on the street
Amazing video as usual, keep up the fantastic content, your videos always make my day, thanks, I love the positive vibes, keep it up !!!
In JS to last one:
function twoSum(array, sum){
const args = []
for(let i = 0; i < array.length; i++){
array.forEach(e=>{
if(sum == e + array[i])
args.push([e, array[i]])
})
}
return args
}
That function return each possibly combination of two number in array that sum the "sum" variable
this is called the naive approach
I would answer this question like a true data scientist. Using matrix multiplication: for the matrix A you could consider the quadratic form e⊤Ae, where e is the column vector whose entries are all 1's.
You might want to code your solution in APL.
0:25 only programmers would notice the ==
the way i thought of doing the twosum question after you explained it was to have two for loops (like a nested loop)
so the outer loop will pick one number at a time from the array
and then with the inner one you check the sum with every other element except itself to see if you can get the sum
and if sumarray==sum then you can easily print the numbers because you already have their indexes from the for loop
can be implemented in any popular language of course
taking the sum and subtracting each element and then checking for the difference in the array was an interesting approach to me
very cool video :) subbed
in this case, the array is sorted. so you don't actually need to double loop through every element in the array. as long as the sum is bigger than the target sum, you can skip the 2nd level loop
@@DogeMultiverse you're right
didnt think of that
@@DogeMultiverse is there a guarantee that any given array will be sorted...?
So the thing is, the solution you thought of definitely works, and it's even the first solution most people would think of. But the problem with it is that it doesn't scale well. If you have an array with a million elements, then you'll need to do a million comparisons and that's just for the first element. On the second one you will do a million - 1 comparisons and so on and so forth. It's perfectly acceptable with a small input but when the array becomes very large running it this way becomes very time consuming, as opposed to the hash map method where you only need to do, at most, a million operations in this example since you only iterate over the array once.
This is an entire topic called "Time Complexity" and it's quite important to keep in mind if your use case requires super efficient code.
It would be really cool if someone just said "A, B, C, D" for the four programming languages.
B, C, D actually exists... 🤣🤣🤣🤣🤣
@@shashwatpandey3556 All of them exist A B C D
@@ndkshr never heard of 'A' though...
But man this would've been epic... 😂😂😂😂
@@shashwatpandey3556 A was created by Grace Hopper
@@ndkshr Man share any article if you find I can't find anything, for Grace Hopper, results says he developed COBOL
For the last question that's how I'd solve the problem (level 0 coding) :
A=np.array([1,3,5,6,11,23])
size=len(A)
for i in range (size):
for j in range(i+1,size):
test=A[i]+A[j]
if test==9:
nb=test
print("the numbers are in index",i,"and",j)
yea that is what i would do idk why the guy kinda overcomplicated it to himself
@@computerprogrammer7942 The guy's solution is actually better, it has a time complexity of just O(n) using the hashmap method.
The nested for loop approach is also known as the naive approach and it has a time complexity of O(n^2)
The funny thing about C is that the "sum of a matrix" problem can just be done like
for(int i = 0; i < length; i++)
sum += matrix[i];
since matrices are almost the exact same as 1d arrays
That depends on how the matrix was created. If the matrix is a jagged array you'll just sum up the pointers with that code.
Real programmers are probably sleeping in their rooms 😂