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THANK YOU so much for the kind words, this just completely made my day 🥰🥰🥰 And yes I believe in genuinely struggling through the problem and not giving up until *absolutely* necessary and no ideas are left. I hope that by making these videos, I can inspire people to have a similar mindset - since it’s always easier to push through hard things with a buddy!! If you’re a beginner, I would highly highly recommend going through the Neetcode 150 problems, by order of difficulty (easies, then mediums, then hards), as they give you the most “bang for your buck” and are more beginner friendly than other lists such as the Blind 75. I’m actually going to be making a playlist of these problems soon, so you’ll have someone to code along to if that interests you!! Ideally I’ll be starting this Monday, with 4x easies per week, then 2x mediums per week, then 1x hard per week - until I’m done! They’ll be similar in style to these videos of me struggling through them instead of providing solutions :) I APPLAUD YOU 👏 for your learning-oriented mindset, and thank you so much again for your kind words. I hope to see you around here more often!! 🥳 Best of luck with your Leetcode journey, and let me know if you end up starting the Neetcode 150 😎💪

@@alejandroill i am already doing neetcode 150 currently in sliding window.

What if i cant even solve the easy ones, what should i do?

@@Thelion106 easy ones are also hard for beginners. Don't give up. Follow Neetcode website's 150 ones. Also do more if you like. If you don't establish your foundation in easy ones with hard workd, you will have a very very hard time in proper interviews and higher dsa. Be honest to yourself. If you can't solve a problem for more than 3 days, and have absolutely no idea, then you may consider looking for solutions. Some topics like bit manipulation and sliding windows will need some help. It is not like you have to start alone. Introductory help is ok.

Wanna run some blue screen Noor? Or Antichess?🤔

That’s so awesome haha, I hope you were able to solve it!! 😁 It was actually my first time implementing a trie too - I always knew the concept and what it’s used for, but never solved a problem using one until now 😂 Let me know if there’s anything you would like to see from my videos that you would find useful!! I sincerely appreciate your comment 🥰

@@alejandroill I was able to solve it but took longer than i've wanted to. (Silly brain moment) IMO you shouldnt really change anything. It's currently used to document your progress and your current format seems fine for it.

Hahaha that happens sometimes 😋 I can speak from experience… 😵‍💫 And okok great to know, I’ll keep the videos coming at you then!! If I may ask, how long have you been solving Leetcode questions for, and what personally motivates you? Are you a student in college, or well into your career? I’d love to know 🥰

@@alejandroill Currently studying a bachelor in CS (got an associates in programming). Mainly doing LC to prepare me for classes and I simply got bored of making regular projects. Also means this journey is getting halted once classes start again. For howlong: I've dabbled in it for 2-3 years but didn't take it serious, started to take it serious this year August. (Serious as looking up solutions to see where mine could improve or for when i couldn't solve it and learn from that.) Currently sitting on 461 solved (295 E, 155 M, 11 H), around 350 are Algo related and the rest is a mixture of DB and JS. Unfort that doesn't really reflect my skill since I'm still not comfortable solving questions around hard (or even intermediate) topics. (DP, Greedy, DAC, etc.)

Ay that's so cool!! 🤩 Are you taking an Advanced Algorithms class within the next few semesters? WOAAAAAAH ALMOST HALF A THOUSAND PROBLEMS HOLY HECK!!!!!!!!! THAT'S INSANEEEEE 😱 😱 😱 And yeah the harder concepts can definitely seem scary to jump into, but in my opinion they're actually the simplest ones of all! It seems super counterintuitive, but for concepts like say Dynamic Programming, it's essentially brute force but caching results to enhance the overall asymptotic complexity (often from exponential to polynomial/pseudo-polynomial time). That's for top-down DP of course, where for variants like bottom-up you might have to think a bit more cleverly about how you build your n-dimensional array and things like that... In fact, the way I learned DP for the very first time and actually understood it super well was from this video alone: th-cam.com/video/OQ5jsbhAv_M/w-d-xo.htmlsi=6y2vsBNErpeVC86n. If you watch it in full, and you're any bit like me, you'll realize that it's a LOT LESS terrifying than what people make it seem out to be! And the same applies for the other concepts you mentioned like Greedy, Divide & Conquer, etc... It'll definitely help to take an Advanced Algorithm's course, but realize you actually already know how these concepts work! If you understand how binary search or merge sort works, you understand DAC! If you understand how Dijkstra's algorithm works, you understand Greedy! If you understand how to solve a problem like getting the n-th Fibonnaci number recursively and why caching breaks down the complexity from O(2^n) to O(n), you understand Top-Down DP! You already have experienced with each of these advanced concepts, and learning to apply them intuitively in the wild I think just takes a good amount of practice :) [Or so I hope, as otherwise what I'm doing will all be useless... 🫠] I'm not sure if you were seeking advice from your comment, but I figured I'd mention this all just in case since it comes straight out of my heart :) I remember being super scared about concepts like DP and P vs NP, until I'd watch a lecture by Erik Dermaine, and feel on top of the world. Having no clue what MSTs were about, how to implement Dijkstra's or even BFS/DFS iteratively, or learning about Union/Disjoint Sets, until watching a video by Abdul Bari. All the concepts seem tough and scary at first, but when you uncover them you realize the ideas behind them are actually very straight forward. And this still happens to me today! Just this morning I watched a short by Neetcode covering Topological Sort. I paused that short and just read the code, saw what he was doing with indegrees -- and now it FOREVER makes sense to me how to topologically sort any graph from now on (or detect that it is not possible). Whereas before today, if I ever encountered a topological sort problem, I'd likely resort to some online solution and not take the time to understand the implementation myself (just what it does). I'm definitely still trying to build good intuition, in just yesterday's video alone it took me 4 hours total to figure out how to write some piece of logic that only required 1 line of code in the end 😵‍💫 But I hope that with enough practice practice practice, solving at least one problem a day over the long term, I can learn to build that good intuition from the small base of knowledge that I have, and whenever I truly don't understand a concept - resort to resources online to learn them at a deep level so I can understand and remember them forever. I realize this is an extremely long reply, I hope that there's at least some utility to be gained out of it 😅 Thank you so much for sharing your Leetcode journey with me, maybe this encourages you to keep solving 1-3 problems per week even when classes start :) Otherwise I look forward to hearing from you until classes start, and thank you so much once again for taking the time to leave a comment on my channel, it really helps and means a lot 🥰 And best of luck with school, that always comes first!!

Hey Prithvi, I’m glad you find my videos as a good motivational resource to keep on pushing!! I’ll make sure to keep them coming your way every single day ☺️ Also, if you want to get the most “bang for your buck”, I highly recommend solving the Neetcode 150 as well (if you haven’t done so already)! These problems are curated to maximize learning outcomes, and I will be filming another series starting next week of me struggling through these problems. They will be exactly similar in style to these daily challenge videos. Let me know if there’s anything I can do that would be helpful to you, and otherwise I’ll make sure to keep posting daily!! It makes me feel on top of the world that you find my videos useful 🥰

Hi Samer, I’m super glad to hear you like my videos!! 🤩☺️ At the moment it says on my profile that I’ve solved a little over 200 problems so far :) I’d love to hear about your Leetcode journey, whether you are just starting out or already a Leetcode veteran! If you any advice for me or similarly any questions you would like to ask me, please share and I’ll make sure to respond to every single one 🥰 If I may ask, what currently inspires you to solve Leetcode problems?? 🤔

Hahahaha yeah, I can’t believe I didn’t notice it, especially when I literally wrote it out in front of my face… 🫠 I’m definitely glad I looked at the solutions afterwards to notice that though 😋

Haha yes!!! I don’t know why but the Leetcode problems have been much easier lately, at least in comparison to August… 😵‍💫

Hey Saag! And haha, yessssssssir 🤩 I only realized it because I was going through the example on my terminal and realized the relationship and then it clicked 😋 There’s always room for improvement though, so I hope to keep getting better over time!! How’s the Leetcode journey been going for you my friend??

My LeetCode journey’s been going pretty great! 😄 I’m not as consistent as you, but I’ve been keeping up pretty well. I’m on Day 25 of doing problems daily and only missed like 5 days so far. When I miss a day or two, I just head to your channel, watch you solve the daily challenge, and it gets me motivated to jump back into it again! 💪

Ayyy I’m so glad to hear! The trick is to never fail on a habit more than twice in a row 😎 I.e. if you are trying to develop a daily habit, never go more than two days missing your habit. It’s definitely okay to skip sometimes hehe 😁 I just keep going nonstop since I know if I stop one day, I’ll wanna stop the other, and wind up down an infinite rabbit hole… 🫠

Thank you Hemit!! 😊 Were you able to solve it??

Don't give up!!! My first contest I was also only able to solve 1/4 questions but I was able to get better and even solve 4/4 for some contests- albeit I haven't done a contest in a while I didn't realize they started adding penalties for wrong submissions- I suggest you keep doing it for a few more contests since I think they've really helped me do better during interview. Also keep in mind contests tend to vary in difficult wildly from week to week so it could just be that this week was particularly hard. One thing that did help was reading other people's solutions after the contest was over. And it's fun to read the comments of some really hard question that I was also struggling on LOL

Hey Ecto!! And thank you so much for the kind feedback, I really appreciate it 🥰 I’ll definitely make sure I go over other peoples solutions everytime I finish a contest, until I get to the point where I can get 4/4 consistently, even if it takes years… 😅 I’ll take your advice to hear and keep going with it though 😎💪 I know we messaged on discord btw, but we should give each other a call sometime - always nice to catch up ☺️

Love seeing you try something new! 😄 It’s awesome how you go back to review the problems afterward 🙌 You should totally keep doing these weekly, even if it’s just solving a couple and reviewing the rest. It’s all about the learning process! 🔥 Keep it up my guy! 🤩

Thanks so much for the advice Saag, I’ll definitely keep ‘em going and review solutions to problems I couldn’t solve at the end each time 🥰 I’ll also force myself to stop after 90 minutes each time as if it was a real OA, to build the habit of working in time pressure slowly but surely 😎💪

Hey Saran! And sure! I’m not actually sure what are weekly discussions, would you be so kind as to explain it to me?

@@alejandroill weekly contest discussions apologies

Sure! I recorded myself doing this weeks, but only solved 1/4 so I don’t know if to upload it or not…😅

Thank you Saag, your comments always mean the world to me 🥰

Bro I have an issue , I just did setup of this extension and solved a problem but nothing pushed to my repository

@@praful_creations_0Oh no way, I’m so glad to hear you’re trying out Leetsync!! 🤩 I will admit that the extension is quite buggy - for example you’ll notice in my videos the UI is stuck at 71 problems solved, but never the matter I’m always able to submit from Leetcode to GitHub. Some troubleshooting tips maybe, I always keep a tab of my GitHub open just in case - but also Leetsync won’t re-upload your Leetcode submission if it’s not different enough from your previous one. Is the issue you’re encountering for trying to re-submit a problem solution? If so I’d say to change it a bit by adding maybe a few lines worth of comments, or trying it with a different problem, etc. Were you able to get it working at least once??

@@alejandroillafter you video , i installed leetsync , did setup and solved over 5 different problems today but none of them were uploaded but I'll try next time to open a tab of GitHub. It's not a big issue , It still records my streaks and how much I solved problem and I even can see my streaks from other tabs so everytime I'll click it it'll motivate me to solve more problems. As i saw your stats 📈

@@praful_creations_0 Ayyyy that’s awesome, it’s definitely a big motivator when you get to see your metrics & efforts compound!! 😎💪 When setting up the Leetsync extension, I think you have to make sure you give it permission to access your GitHub repository and specify a new repo for it to start pushing your changes into. That’s why I get a little nervous recommending the extension in each of my videos, since they do technically have access to your GitHub, but if you trust the extension as well then it’s no issue - but definitely need to ensure that it was configured correctly 😅

Haha yesssssssir, can’t miss even one day, no matter the reason 😎💪 (even if I’m on a 24-hour flight, they better have purchaseable wifi 😂😅)

WOAAAAAAAAAH, thank you so much for this feedback, this is AMAZING!! 🤩 I was definitely wondering about the bugs from (1) and (3), I didn't want to spend too much time thinking about it during the video since I had board-game night with my friends (I swear they always play my favorites while I'm recording... 🫠). For point (1) it definitely makes sense why that matters, in having to align with the obstacle positions. For point 3, that's such a bummer I didn't take 5 more seconds to investigate the issue 😭 I suppose if I changed checking new_pos to just (x, y) it would have worked, since (x, y) is now the current furthest position I can reach from taking the up-to k steps forward... 🫠 I gaslighted myself into believing that it's likely some edge case where the furthest position can be somewhere in the middle of the k-steps, which of course doesn't make sense now that I think about it after-the-fact 😔 I highly highly appreciate you for letting me know, that definitely clarifies it for me BIG time, and I'm actually gonna pin this comment cause this is amazing!! For point (2) that's actually a neat little trick 😯 I've never used an enum in python before, although I'm sure there's at least a library for it, so I always come up with something janky and hard-code the directions in these kinds of cases (since there's very few of them). But I completely didn't think of making them 0-3, and just adding by one + modulo-ing by 4 each time! And turn left I suppose you're adding by 3 since turning right three times essentially simulates the same result as turning left once -- that's actually so genius 🤯 Man I've got to say I REALLY, REALLY appreciate your comment, this is so insightful!!! This comment 10000% deserves to be pinned, I can't thank you enough for taking the time to write these details here to help me and potentially everyone watching!! You're the man @theragaru 😎💪 If you don't mind me asking, I'd love to get to learn more about you, what inspires you to do Leetcode, how long you've been doing it, and what your goals are!! Are you maybe a competitive programmer, a student, or someone trying to land a job? I would love to know!! Thank you so much once again for your insightful comment, it's always super helpful to have someone check & review your work, especially in Leetcode! If you find these kinds of details to comment on in my future videos as well, please feel free to point them out as it really helps me learn, and I’m sure others as well!! Thanks again @theragaru, and here’s a big cheers to you 🍻

@@alejandroill game night should always take precedence! you definitely would've realized the bug if you took the time I'm a faang type engineer grinding leetcode for interviews. I think your channel got recommended to me because I've been watching channels like NeetCode😆 it's been cool to watch someone else do the problem from scratch to see what intuitions/steps I may have missed, as opposed to watching someone just review the problem already knowing the answer. thanks for uploading!

Haha hopefully and omg no way, that's so cool!! I work at Microsoft myself as a SWE, although I know that's technically not FAANG 😔 (or is it MANGA now? 🤔). And yeah that was definitely the goal!! I noticed that almost every other Leetcode channel would present the raw solutions themselves, instead of showing the struggling & thought-process that would arrive towards the optimal solution. One thing I realized VEEEEEERY quickly during University is that understanding the solution to a problem is MUUUUUUCH easier than trying to come up with the optimal solution yourself 😅 So I figured by making these types of videos they could either be used to code alongside to, or to see step-by-step how one may go from Idea 1 to Idea 2, ..., to Idea N until reaching a finally working solution 😊 And of course!! If you ever have any feedback or want to keep having a conversation going together, please always feel more than welcome to do so!! I sincerely appreciate your comments and informative feedback @theragaru🥰

YESSSSSSSSSSS I’m so happy about that 🥰 FIRST BADGE ON THE CHANNEL!!! 🤯🤯🤯

Oof, I could certainly give it my best shot, though I’ve never coded in C++ before. I suppose it can’t be too much different from C… I like Python (even though it’s MUCH slower) since it allows you to focus less on implementation details and more on solving the actual problem. Even something like converting a uint to a string or vice-versa might be trivial in Python but a nightmare in C++ 🫠 It depends on your goals however, I know most competitive programmers tend to resort to C# for solving these problems to make their solutions as fast as possible 😁 One thing that’s nice about Leetcode is that even though Python is much slower, your submissions get ranked against other Python solutions, so you can already reasonably-gauge how efficient your solution compared to others. Let me know what motivates you to solve Leetcode and what your goals are, and maybe I can try writing some of these solutions in C++ as well - although fair warning that I’ve never coded in the language before 😅

@@alejandroill No worries 😄, You are great In Python 👍 I was just asking , cause i was not getting it's solution 😅 that time. but u did it very well and Congratulations for your BADGE 👏

Ayyyy thank you so much @praful_creations_0!!! 🤩 And ahhhh I see, and yeah it might be tricky in C++ since I’m not sure if it’s similar to Java & C# where you have a bunch of libraries you can resort to for common DS like hash-sets (since I don’t know of any in C). If it helps and you’re new to Python, or at least would benefit from a brief review of the most useful parts of the language for solving Leetcode problems, I’d highly recommend the video titled “Python for Coding Interviews - Everything you need to Know” by Neetcode. It’s the video I watched before I started solving Leetcode problems, and it’s SUUUUUUUUUUPER useful. That’s where I learned about tools like collections.deque() and heapq that I didn’t know about before, and it really is legitimately “everything you need to know about Python” for coding interviews 😁 Let me know if you find it useful, and thanks again for your super kind comment, these really help keep me going 🥰 I hope to keep hearing from you my friend, and let me know where you’re at in your own Leetcode journey!!! 🤩🥇

@@alejandroill bro i Really appreciate you , Like you are replying in such a big paragraph, that takes lot of effort. I wish you will achieve a great success on your TH-cam journey ⚡😌

@praful_creations_0 The pleasure is all mine! From my view you guys kindly take the time out of your day to leave a comment on my channel, so it’s only fair that I give my most well-thought-out response every single time 🥰 I really appreciate your kind words, and I can’t wait to see how this puppy takes off over time!! 🚀 If you ever have any suggestions or types of videos that you’d find useful or would like to see, please let me know ☺️ Rock on my friend, and best of luck with your Leetcode journey too!!🤘🏻

AYYYYYYYYYYYY 🤩🥇🤩

Hey @kruttichhwas, welcome to the channel!! I solve the Daily Leetcode Challenge (DCC) every single day, which is a random problem listed by Leetcode that releases every day at 5:00 PM PDT. It can either be a Leetcode Easy, Medium, or Hard problem 😁 You’ll see in the beginning of my videos I always click the little fire on the top right-hand side of the website for the new daily problem, and the number besides it represents how many days in a row you’ve been solving Leetcode problems!! I do it since I like the idea of being able to keep a visual streak going and helps keep me consistent with it - but if your goal is to become as good at Leetcode and as quickly as possible, I would definitely recommend doing something like the Neetcode 150 instead of the Leetcode daily’s (as those problems usually give you WAAAAY higher “bang for your buck” than the average problem on the platform). Let me know what your goals are and what motivates you to solve Leetcode problems, and I’ll do my very best to help out if that’s something you’d like!! Thanks again for leaving a comment, I highly appreciate it 🥰

@@alejandroill I’ve fallen out of practice with solving daily problems, so I’m trying to get back into the groove and keep that streak going. I'll definitely check out the Neetcode 150.

Ahhhh I see, in that case yeah - the Neetcode 150 is a GREAT starting point to re-sharpen those skills 😋 I left some very detailed advice in one of my replies to Maurice in my Day 43 video in case you’re interested, but otherwise as a TLDR: I’d recommend solving the Neetcode 150 in the order of topics they’re listed (Arrays & Hashing, Two Pointers, etc…), and by first doing the easies for each topic, then coming back to do the mediums for each topic (i.e. starting back all the way from Arrays & Hashing all over again, and etc.), and then even repeat with the hards if you reach that far! These problems are great in that they each serve in learning an important DSA & Algorithms concept. Some of them like Contains Duplicate (the very first easy) may seem trivial, but for people who haven’t seen (or didn’t think of using) a hash-set, it’s a great starter lesson! And even if so, it’s a great starter problem to get you feeling confident right out of the getgo 😎 I wish you the best of luck with your Leetcode journey, and I hope you stick with it!! Feel free to use the comment section to keep me updated about your progress from time to time, which problems you like most, and if there’s any videos / topics you’d like me to cover (maybe I should make a Neetcode 150 playlist 🤔). Thank you once again for your comment @kruttichhwas, cheers to you my friend 🍻

​@@alejandroill You should totally make a playlist for solving the NeetCode 150 with your style of videos-showing your thought process and everything while solving the problems. 🤔💡 I haven’t seen anyone else doing that with NeetCode 150, and I’d love to watch it! 🙌🔥 Would be super helpful for so many people!

Oooooh you think it would actually be useful?? I could totally do that, if I do 3 problems a week that would get me there within a year 🤔 I might make a playlist and just start solving those over the weekend, even if it’s just one a week 😁 I’m also considering whether I should start doing the weekly problem challenges as well, but I also don’t wanna do too much yet where I burn myself out 😅 I probably will start building a Neetcode 150 playlist with 1-3 videos posted every weekend 🤩 Maybe I could even do it again a years time from now, to see if I get better each year, and even do like a 12-24 hour marathon of solving them all in a row if I’m quick enough 😂 But for now, I’ll see if I can get those weekly uploads going!! Thank you so much for the feedback Saag!! 🥰

YOOOOOOOOOO NO WAY, ECTO IS THAT YOU???! How is literally everybody from uoft finding my channel 😭 How’ve you been man??! Let’s get on a discord call and catch up soon if you’re down :)

Hey Leon, it's super nice to meet you!! 🤩 Which campus do/did you go to if I may ask, I was a UTSC student hehe 😋 And that's great to hear!! There really is no "secret sauce" for getting good at Leetcode, all that matters is that you (1) start and (2) stay consistent / don't give up. 😎💪Seems like you've already completed step 1, and feel free to use this channel as motivation to keep going with step 2. I find it's always easier to stay consistent when you have a friend or someone you know doing it with you!! I wish you the best of luck with your University studies Leon, how far along (i.e. which year) are you?? I'd love to hear from you on how your Leetcode journey is going from time to time, and thanks again for leaving a comment on this channel!! 🥰 Cheers right back at you Leon 🍻

​@@alejandroillhi Alejandro, I'm from the mississauga campus, I've actually been to utsc a couple times for summer school, I remember there's observatory in one of the buildings which is really cool. I'm in my final year, starting school tomorrow (Sep 3). It's true that one needs to be consistent with the leetcode practice to be good at it. I've been trying to stick to doing questions on leetcode, and I hope I can reach your level of tackling daily questions. Whatever your goal is I hope you succeed. -Leon

@leonyao4432 Oh that’s so cool, I actually took PHLB50 over at Mississauga (super bird for CS students hehe 😉). Best of luck with your last year, CONGRATS for making it this far!! 🥳🥳 It’s definitely not easy with all the things they throw at you, I still remember the nightmare of first year POSt 😵‍💫 You’re in the home stretch Leon, don’t let senioritis get the best of you haha 😁 Is your last year CS-heavy, or did you mostly finish your major/specialist to make your last year more chill? I’d love to know which courses you’re taking during fall and winter :) And if you need any course recommendations, whether for CS/electives, let me know!! Thanks again for your kind comments Leon, and I hope you may also succeed with your goals too ❤️ Cheers my friend 🍻

Hey there Kelper, thank you so much for your kind comment!! It's messages like these that inspire me to keep pushing forward, so thank you sincerely from the bottom of my heart 🥰 And yes for sure, we'll all make it one day for sure 😅 Just gotta remember that consistency is key 😎💪 I would love to hear about your own personal Leetcode journey, what motivates you to solve these problems yourself? 😯

@@alejandroill I'm not into leetcode yet actually , I will start my learning journey today inşallah and someday maybe I'll tell you about my progress.

Oh no way, that’s awesome!! If you can take that big step forward, you’ll quickly come to realize that (1) getting started and (2) keeping consistent with it is the secret to becoming good at Leetcode 😎💪 And yes definitely keep me updated if you decide to start!! If I may ask, is there something that motivates you to begin solving Leetcode problems? Whether it be to get an internship, a job, or to learn/get better at DSA & Algorithms knowledge?? I would love to know!! 🤩

@@alejandroill My motivation is to improve my thinking skills and to be able to solve problems in several creative ways , in conclusion the answer is "to widen my horizon"

​@@Jxs.911 Oh no way, that's so cool!! I think Leetcode is a WONDERFUL way to achieve that, I find that it often requires me to think creatively more than it does analytically 😋 It reminds me of solving integrals or even in chess, where sometimes you have to rely on long-term ideas based on intuition & practice instead of relying upon brute-force calculation to think ahead 😁 I absolutely love that you're doing it for this reason, it will definitely make it easier to stay consistent, especially as opposed to cramming as much information & practice as possible, as quickly as possible 😅 Huge kudos to you for doing this 🍻, and please keep me updated from time to time on how it's going! Are you thinking of solving a problem each day, once per week, or something else? Let me know!! 😊

August DCC badge acquired! LET'S GOOOOOOOOOO 🎉🎉🎉

YESSIRRRR 🤩

Hahaha don’t you fret my friend - I purposely took my time on this problem to go slowly so that I wouldn’t fall into any traps in the beginning. 😅 The first hour alone was just me writing Dijkstra’s from scratch, so that I could solve some trivial no-solution base cases 😵‍💫 You got this Yash, and let me know how it goes!! Don’t give up until you run out of good ideas, or spent more than 1-2 hours on this problem, and you’ll become a monster at Leetcode 😎💪 Best of luck!! 🥳👏

@@alejandroill Yes, I won't give up. I was suggesting solving on a whiteboard and saw you did on your ipad. I'm gonna spend a good amount of time here. Thanks a lot again for this. You are doing an outstanding job giving your valuable time here

Hey Yash, thank you for your kind comment ☺️ And yessss I’ve definitely thought over and over about investing in a whiteboard setup, not only for my explanation during leetcode videos - but because I also want to start uploading educational videos separate from the Leetcode (Maybe Algorithm explanations, introduction to writing proofs, symbolic logic, etc.)!! The only problem is that my room is so small that it’s hard to figure out how I can setup a proper place for both the whiteboard for me to write on and a camera to record me with enough space in between. My employer does have good setups in its in-person offices, but not sure if I’m allowed to use company WiFi for personal use so I’m refraining from trying that for now 😅 But I’ll definitely try to figure out someway of getting around that, because it really would be super useful in my Leetcode videos as well!! I could even post shorter complementary solution videos to the problems I record myself struggling through as well, with the whiteboard for visualization help - there’s so many ideas! The iPad was a small temporary solution since I couldn’t use much else… 🤓 Did you still find that part useful?? And of course, it’s my absolute pleasure, though I’d like to relay the thanking back over to you for being such a kind supporter, I really appreciate it from the bottom of my heart ❤️ Let me know if you were able to finish the problem, it’s definitely a tricky one!! 😵‍💫

@@alejandroill the ipad absolutely works until you find an alternate solution and it was really helpful even though you showed screen to the camera i could see and understand everything

Okok that’s great to know!! I’ll keep doing that from now on until I find something better - I’ll also checkout if there’s a way for me to share my screen on the iPad while I’m recording, because that would be an absolute GAME CHANGER 🤯 It would even solve the whiteboard problem entirely, and in an even better way!! 😮

Hey there Asad, thank you for the kind comment!! ☺️ You’re definitely right in that it might not be the most efficient way of doing things… 😵‍💫 It’s probably much better to set a max cut-off time for each problem - especially if your goal is to become good at Leetcode as quickly as possible… 😅 It’s just like the gym though, no matter which way you do it, what counts is (1) getting started and (2) being consistent with it! With that 1-2 punch formula, you can become competent in almost anything in life, with Leetcode being no exception 😎 Stay strong Asad, and let me know what motivates you to start Leetcoding!! I would love to hear from you, and thanks again for leaving a comment on my channel 🥰

Hey Maurice, it's super nice to meet you!! And yes absolutely, I would definitely recommend starting small until you're comfortable solving easy problems before moving on to mediums. A great resource for doing this would probably be something like the Neetcode 150, where he sections off each DSA & Algorithms topic by category, starting with Arrays & Hashing, Two Pointers, Sliding Window, etc. I would recommend solving all the easies for Arrays & Hashing, then all the easies for Two Pointers, Sliding Window, and so on in the order listed on his website. If your goal is to land an internship or full time job, I would probably skip sections like Tries, Intervals, Math & Geometry, and Bit Manipulation, as I notice they're rarely asked for during interviews. Then once you finish all the easies, I recommend going back in order of Arrays & Hashing, Two Pointers, Sliding window, etc. but doing the mediums now instead. This is exactly what I did when I grinded Leetcode for the first time a few years back. These problems are good in that they give you the "most bang for your buck" in regards to learning outcomes. They are curated to be make you confident in the beginning with problems like "Contains Duplicate", but simultaneously require fundamental understanding of a core idata-structure and/or algorithm to solve every one of them -- making them very powerful for learning. For instance, in the case of "Contains Duplicate", the core idea is in understanding the efficiency tradeoff from using a hash-set (which allows you to lookup an element in constant/O(1) time), as opposed to a regular python list or array (which requires linear/O(n) time). Neetcode is a TH-camr who also posts solutions to each problem that are very to-the-point, simple, and often easy to understand (with much better explanations + visuals than in my videos!) Though I should give fair warning and say be careful with this, since one thing I realized very quickly during college is that: understanding the solution to a problem is NOT the same thing as actually solving the problem yourself. The overall learning outcomes are usually very different, where if you focus solely on understanding problem solutions, it becomes very difficult to develop a good sense of intuition for solving similar problems or ones that involve similar ideas in the future. That's actually why on this channel, I make an effort of struggling through the problems instead of publishing solution videos. I do this since: (1) I don't think I could beat the master of Leetcode at his own craft 😂, but more importantly… (2) to demonstrate what a balance between struggling through problems versus trying to understand the optimal solution can look like, if your goal is to maximize for learning outcomes and becoming as good as possible at Leetcode. I find that in just watching Leetcode solutions it can be a bit en-trapping, in that it doesn’t always reveal how to develop a good sense of intuition that you would get from actually trying to solve the problem yourself. That’s why in my videos I try to showcase how I come up with ideas & approaches to solve the problem, even if it doesn’t always lead to an optimal solution. Of course, the reverse is also true, in that it serves very little purpose to spend countless hours on a problem with no avail without looking at the solutions (I'm definitely guilty of this sometimes 😵‍💫). Often times Leetcode problems have hints, but even if those are not enough, you should absolutely look at and try to understand the solution when you get stuck and don't have any ideas left. In fact, I think not only the best (but also fastest) way to become good at solving Leetcode problems, is to set some artificial time limit for each problem. This can be anything, but if you need a good place to start, something like 30-60 minutes for easies, 60-90 minutes for mediums, and 90-120 minutes for hards should be reasonable enough. Struggle through the problem until you either solve it or run out of time, and try to understand the solution if you did run out of time. If that happens, make sure to mark the problem so that you can refer to and re-attempt it again in the future (i.e. maybe 1-3 weeks later), in order to make sure you truly internalized and understand the solution and the core idea/lesson behind it. The advice of using a timer is especially important if your goal is to land an internship or a job, where you don't have an infinite amount of time that you can afford to spend solving Leetcode problems. Time is valuable, and this technique is similar to following a routine like doing 3-5 sets of 6-12 reps of an exercise at the gym, instead of trying to take every single set until failure. The latter requires a lot more effort, for maybe marginally better results, if at all. If you want to not only get good at Leetcode but do so as quickly and efficiently as possible, I would definitely recommend a strategy like this instead of spending too much time on a problem without looking at the solution. There's definitely a lot of things I'd love to share here and there to accelerate the learning process, maybe I should even make a video about it at some point haha 😁 But the most important part is definitely to start and staying consistent. If today you decide to start solving the Neetcode 150, going in the order of the categories listed, doing the easies of every category first before going back to them to do the mediums, and applying the timer technique to make sure you don't ever spend too much time on a problem (but also mark the ones you had to look up solutions for to re-attempt them in the future) -- there is almost no way you don't become an absolute BEAST at Leetcode within a few months. This is exactly what I did when I was a Junior in college, it definitely paid off very well when I was applying to internships, and landed offers from companies like Amazon and Microsoft (where I now work today!!) Otherwise I wish you the absolute best of luck with your journey Maurice, let me know if this advice was useful and if you decide to apply it! By the very fact that you are asking this question I can already tell that you are a motivated person, and if you do decide to apply this advice, I would love to hear from you on what motivates you to begin Leetcoding and on how your journey is going! Just remember that consistency is key, and that the most important thing you can do is to start: even if everything seems overwhelming to you at first. Huge kudos to you Maurice, and let's get on this Leetcode grind!! 🤩

@@alejandroill Thank you for the advice! I will be sure to use those strategies while continuing my journey, especially the timer. I am a junior in university and I started leetcoding about a month ago. I did my research and saw that leetcode was very useful when interviewing for jobs. One of my goals is to get an internship by the summertime. I will keep grinding and trying to learn more each day. Again, thank you for your words, everything is very helpful!

@@alejandroill I absolutely love how you give such good advice and reply to everyone's comment. Love the work that you are doing ❤️. Your words are pure gold.

It’s my absolute pleasure!! And it’s funny you mention that Maurice, since when I mentioned I started Leetcode a few years back… it was also during my Junior year of university!! What a coincidence 🤯 And yes absolutely, Leetcode is super important for being able to pass the technical interviews. I’ll share a little secret with you that I realized when I was in university: everybody knows that they need to solve Leetcode problems to be able to pass technical interviews, but only very few (often much less than you think) ACTUALLY do it!! At least to me, this was a great motivator for taking Leetcode seriously - and it worked out in my favor! You don’t have to go as hardcore as I did by sacrificing school learning & grades to grind Leetcode (I only did this since my primary goal at the time was landing a good internship), or by going overboard with the time spent per question, but by being consistent and doing a little every day you’ll become better and better, until you can consistently solve most mediums in about 45-60 minutes - in which case you’re 100% interview ready 😎 I say this because most of the time, the questions you’re asked during interviews are often at most a Leetcode Medium in difficulty. Some exceptions might be Quant Firms, sometimes Google, or even most companies if you get a bit unlucky. For instance Amazon asked me a Leetcode Easy, while my friend got asked a Leetcode Hard in his interview right before mine. If you get asked a hard in an interview you though, don’t let that discourage you - often times the interviewer understands that it’s a hard question and mainly cares about your thought process throughout the problem, not necessarily whether you were able to find the optimal solution or not. This actually happened to another friend of mine, who got asked a Leetcode hard for their interview at Amazon, but were able to do well enough on the behavioural + presenting good thought-process and a working (albeit not-optimal) solution to the problem. Nevertheless, I wish you the absolute best of luck with your journey Maurice, and I hope that you may find my channel to be a useful resource during your Leetcode grind!! 🤩 Just by being active here and asking these kinds of questions I can tell you’re serious and committed, which is all it really takes to become a champion 😎 You got this Maurice, I hope to hear from you from time to time about your progress, and always feel free to have a chat with me and/or ask me questions - I’m always there and happy to help!! Kudos to you Maurice, and let me know how everything goes. Cheers!🍻

And thank you so much Saag, your support always means so so much to me. I’m very grateful for the kind people like you I get to encounter in life 🥰 I hope the Leetcode journey for you is still going strong!! 💪 How’s it been for you lately??

YESSIRRRRRRRRR 🤩🤩🤩

Thanks for always being my #1 supporter Saag 🥰

You're the one who motivates me to keep up with LeetCode daily! 🙌🔥

Hey there Yash, thank you so much for your feedback!! I think that's one of the kindest things someone’s told me in a while 🥰 I'm really glad to hear you find the videos enjoyable to watch & code alongside to, and yes absolutely - I would love to add you on other social medias!! I don't have a Twitter account, but I do have a LinkedIn profile - my alias is @alejandroill, feel free to send me a connect invite and I'll accept your request 😊 I'm really glad to hear you stand committed to solve these daily Leetcode problems with me, consistency is the best way to become great at anything 😎💪 Feel more than welcome to use the comments section (or LinkedIn) to continue having a chat with me, I would love to hear about what motivates you to solve Leetcode problems yourself!! I wish you the best of luck with your goals and journey Yash, and thank you so much once again for the extremely kind comment 🥰 Let's get on this Leetcode grind my friend!! 🤩🍻

sorry for spelling your name incorrectly, that was a keyboard error and I do not claim it 🎯

Hahahaha no worries, and there we go - I fixed mine as well 😉

@@alejandroill Lovely, see you on LinkedIn 🙏🏽

Added you!!

Hahaha thank you so much, and welcome to the channel!! 🤩 I’ve been Leetcoding daily since about end of May, but started recording them around mid-July 😊 I did grind Leetcode kind of seriously for a few months 2-3 years ago when I was applying for internships during my Junior year of college. Once I was super fortunate to got an offer though, I kind of toned down on solving Leetcode problems to focus more on finishing my undergrad :) I will say if there’s anything that definitely prepared me most for Leetcode-style DSA & Algorithms problems, it was most definitely my advanced algorithms course in University. My professor actually lists his advanced algorithms course site publicly on the internet, including a lot of his notes, which are some of the best I’ve ever read (very short and succinct, but packed with so much detail you’ll feel like you’re reading a Harry Potter book!) If you’re interested in that resource just let me know and I’ll send you the link :) The first half (more Leetcode-like focused) is mostly about solving optimization problems, which is why in my Leetcode videos I always resort to “Greedy / D&C / DP” whenever I see a min/max optimization problem 😁 Then for the second half he also covers concepts like problem reductions, such as Linear Programming, Max-Flow / Min-Cut theorem with Floyd-Fulkerson algorithm, etc. Very cool and useful stuff, especially if you like the “problem reduction” approach I take on solving some of these Leetcode problems 😎 I hope you may find my videos helpful and enjoyable, I give you my sincerest warm welcome to my channel, and please let me know what motivates you through your own personal Leetcode journey!! I would love to hear from you 🤩

Haha yeah… 😵‍💫 I realized my mistake later on, where I had good intuition in that with a correct heap implementation of Dijkstra’s I could reduce the problem from O(n^2) time to O((n+m)logn) time, by keeping at most O(n+m) elements in the heap at a time. The heap implementation is only worse when the graph is dense (i.e. m = O(n^2)), but for this problem we were given that n <= 10^4 and m <= 2*10^4, hinting that with max values for n and m, we have that m <= 2*n. Although my idea & realization was correct, my solution was actually still at minimum O(n^2) (if not O(n^2logn)), because I was looping through all edges and ignoring ones I don’t need for every node in the Dijkstra’s main loop, where in a worst case scenario means I loop through all edges on all n iterations. The trick was to make use of the fact of only traversing every edge once when needed, even if one iteration of the for loop went through many more edges than another (not necessarily an even split), but keep it at an upper bound by using an adjacency list. That way instead of looping through all edges in each iteration and skipping over the ones I don’t need, I only iterate over the ones I need, potentially saving me LOADS of computational work. It was a small detail I definitely overlooked, but glad I was able to make that realization and fix my code as such in the end. This could have all been prevented if only the heapq Python library supported a way of changing the priority of a node in O(logn) time… 🫠 But in the end learning only comes through struggle, so this wasn’t in vain and in the end I learned how to implement Dijkstra’s algorithm with the heap implementation in Python efficiently, even without a CHANGE-PRIORITY support method from heapq library 😎

Haven’t seen the video yet, but I will after work, I’ll try to learn how you applied Dijkstra and heaps

Hahaha, it’s always works that gets us 😵‍💫 And sounds good, let me know if there’s anything more I can clarify, I’m always super happy and ready to help when needed 🥰😁

Hey there Joe, it’s super nice to meet you!! 🤩 Hahaha, it would probably be similar difficulty, if not a little harder! Numbers like One Hundred would be “cien” whereas any other hundreds number is spelled with “…cientos”, without a space, so I’d say there might be a few more edge cases with places to remove spaces if the problem was in Spanish, but other than that it would likely be very similar or the same in regards to difficulty 😎

Hahahaha yessssss, although I wonder what that means is in store for us the next 1-3 days difficulty-wise… 🫠 Hopefully no back-to-back ultra hards 😅 AND YES OMG SO EXCITINGGGGG, ALMOST THERE!!! 💯🤩

Ayyyy, I’m so glad to hear that José!! 🤩 It’s amazing to already see you progress, that means you were able to internalize the solution well yesterday, which is otherwise a big trap that people can get into when building new projects or grinding out a technical skill like Leetcode. So big kudos to you my friend, and let’s keep the Leetcode problem solving streak going 😎💪

Hey there, thanks so much for leaving a comment! I had to search up what you meant -- I actually had no idea that Leetcode had follow up questions!! I'll definitely have to take a look and share my thoughts (or even solve them) in my future videos from now on. Thank you so much for the suggestion!! 🥰 As for this problem specifically, one thing we learned in my CS class back in college was drawing out the traversal methods (preorder vs inorder vs postorder) to get a better sense of intution with each, as it was meant to warm us up to understanding the recursion method. One thing I noticed is that for preorder you added nodes to the result the first time you visit them, for inorder the second, and for postorder the third time you traverse them. That works for binary trees, but in this problem where a node has say K children, you then add the node to your result array on the (K+1)th visit. So every time you traverse a node, you would append it to a dictionary with its value set to the number of it's children (if not seen before), and otherwise subtract 1 from its dictionary-value (and append it to result array if its value is now 0, hinting it's the K+1th time we visit the node). That way, the result array would then get populated in correct postorder traversal. I hope that explanation is useful, in case you wanted to have a mental roadmap of how I'd tackle the problem iteratively; though I just want to quickly say thank you so much for giving me that feedback, I will 100% start to watch out for follow up questions in my future Leetcode problem-solving videos 😁

Hola!! Me alegra que te haya sido útil, y muchísimas gracias por tu comentario!!! 🥰

Hahaha yeah, today was literally me applying one idea and then plumbing through the edge cases one-by-one until I reached the solution... 🫠 Thank you so much Saag, always brings a smile to my face seeing your comments on my videos 🥰

Heck yeaaaaaaah, was definitely well needed 😅

YES SIRRRRRR!!!!

Hey there Prithvi, and welcome to the channel!! 🤩Thank you so much for the positivity! 🥰 I would love to learn about your own personal journey, what motivates you to solve Leetcode problems??

Ayy thank you so much for the feedback Saag, you have no idea how happy it made me to read that 🥰 And YESSSSSS omg, it probably would have bugged me everyday about it if I didn’t fix it… 🫠 Glad it’s resolved now hahahaha 😅😂

Haha don’t worry don’t worry, I fixed it and explained in the next video 😎💪

Hey Suraj, it’s super nice to meet you!! 🤗 I sincerely hope that it can, and motivate you to keep on pushing every single day 😁 One big thing that inspired me, which I learned from the book Atomic Habits by James Clear, is just how powerful becoming even 1% every day can be. 💪 For example if you become 1% better everyday for a year, you end up becoming 37x better than when you started 🤯 Let me know what inspires you to begin or push through your own leetcode journey, whether it be for personal goals, or to land a job, I would love to hear about it ☺️ Thank you so much for tuning into my channel Suraj, and I hope that you’ll stick with it and hear from you from time to time 😁 Much love brother, and thanks for the positivity ❤️ Let’s get on this grind and become the very best developers / problem solvers we can possibly be 💪😎💪

Haha yeah, the left & right swoop efficiency trick really stumped me in trying to incorporate into my top-down DP approach 😵‍💫 I did end up conceding towards the end, but at least I tried my absolute hardest and that’s what matters 😎💪 Thanks so much for the positivity Saag, I always look forward to seeing your comment every single day, it always helps keep me going 🥰❤️

Yoooo Omar, thank you so much for that comment, I really needed to hear that today especially after todays problem 🥰 I really appreciate your positivity, and let me know if you wanna have a chat and tell me about your own leetcode / computer science / developer journey, I would love to hear about it!! 😁

Haha heck yeaaaaah that’s the goal!!! 🤩 Love the spirit 💪 💪😎😎😎

Haha yeah, they gave us an easy problem to solve today 🥰