Doing more these kinds of things is very helpful, especially how u approach them. Teachers normally tell us the optimal solution but how to get to that or how to come up with that solution is not normally taught to us.
I thought of your initial solution right away but would have NEVER thought of the better way. These types of videos are EXTREMELY helpful in reprogramming the way I look at a problem. Thank you!!
I definitely want more videos like this! You're an excellent teacher. I'm trying to get a job as a Java developer and I'm freshening up my knowledge. I will always come back to your videos. They are fun, interesting topics, easy explained and very helpful! 😃
If you struggle with finding a first job, try to look for testers, then get to automate tester, then you will be a perfect java coder because you know how stuff should work. Requirements for junior tester are so little, it is easy to apply
More of these types of videos would be fantastic! Your explanations throughout all of your videos are incredible, and I just started tackling coding challenges and I've been struggling with how to even begin. Appreciate your channel so much!
Great solution. You can decrease the memory footprint by not bothering storing the complement/index of values that are greater than the target as those would require negative numbers to achieve the target.
@@tonypsilon_gaming3221 Fair enough. But 1 question that I would ask is if negative numbers are possible in the source array. But since this is an online test, which can be submitted multiple times, I'd assume as much and run my answer to see if it fails any test cases... If it passes all test cases, then I would add a comment explaining the optimization.
From what I know first solution is: O(n*(n-1)/2) and for the outer loop you should do: for (int i = 0; i < nums.length - 1; i++) Of course it still can be simplified to O(n²) - but never really understand why. I mean it's quadratic, but still quite a reasonable difference to loop i and j from 0 to end. (about half the time of O(n²), which I think is still a difference, especially if it is longer, like from 20 mins to 10 mins)
All of your videos have been so incredibly helpful to a career changing CS student like myself! Leetcode has always seemed super intimidating but your teaching style really makes them seem doable. Please do more like this!
Hi John , waiting for the next episode , it will really help to broaden the logical thinking . I'm a java developer, but never imagined hashmap can be used in such a way.
In order to create a stash of solutions to common problems, I'd love to see more of such videos, taught by someone who really knows what he's doing and who can teach in a clear and straightforward manner. Thanks for sharing this knowledge.
Thank you John for taking the time in creating this video! Please do more of these videos as it teaches problem solving skills and how to walk through the creation of an algorithm. Thanks!
Great solution! One small thing, i think we can reduce the runtime to 1ms by calculating list size out side the loop and do the iteration on calculated size ,otherwise, in each iteration in the loop java will take sime time to calculate the array size int size= nums.length; map=..... for (int i = 0; i < size; i++) { .... }
That thing you said at the end... That makes me feel so much better about myself. I used to feel like there's something wrong with me, but it's natural, apparently!
Dude!! Thanks a lot for this video!! I was straggling with this same question in the AlgoExpert, and I couldn’t understood the Clément's explanation. You explained SO MUCH better, and for free... Please launch a course of Algorithms and Data Structure. I'll definitely pay for that.
As a mostly self taught dev, I really appreciate your content. It has helped me grasp concepts I've been struggling with for a very long time. Thank you!!
It took me a week to "sink in " but I solved my first leetcode with this video , thanks God this video Exist and Thank you John for creating such an amazing video .
Thank you for covering such problems and that too in detail. We usually don't get such insights when doing things alone. Please park some time for adding such videos regularly. Thank you
Yes more leet code/algo videos, there’s barely any good Java leet code videos on TH-cam. Mostly just python and JavaScript videos. Java is neglected on leet code.
I'm new to this channal. Before I saw this video I don't knew what is really hashmap is but after seeing this..... Nothing to say. This video is really helpful. Thank's for creating this awesome video.
Thanks for the encouragement at the end. My solution is close but not quite optimal. It's O(n) space complexity but O(2n) time complexity. I felt bad about not thinking about the hashmap solution until you gave your encouraging words at the end! Thanks man 🥺
Thank you. This was super interesting (to me, anyway). Please give us a few of these every now and then - I'm not asking you to make it exclusive, but it was fun.
I really needed to hear that last bit in the end. im a 2nd yr cs student and ab to do my first technical test for an internship n i find them very hard and even thought of dropping out lol. so thank you
Would definitely like to see more challenges! Never would've thought about using a hashmap and like you said, one more thing I've learnt. Thanks a million. You're a great teacher!
Please do these kind of videos.. because of your great explanation about hashmap now i understood it.. Before i know what is a map, set but i don't know how they actually work..now i know Thankyou
9:44 The solution will return [2, 2] for a target off 8 which is incorrect since the same element is used twice. The code for the "i" should be for (int i = 0; i < nums.length - 1; i++) {...} For the i, j loop version.
I really appreciate the message you start to give at 21:57 - I have been feeling very discouraged as of late trying to sharpen my problem solving skills and it was very comforting to hear that. Thank you!
I have to agree with the majority of the other comments - your explanations of algorithms for solving LeetCode solutions (well, in general good software algorithms) are some of the clearest I've seen. This is probably going to be a new subcategory of videos that you might not have planned to do, but I can see there's so much interest you have no choice but to do them! (Please?)
Yes.. Nice. Coding is not just getting the correct result. But it also getting the result in correct/optimal way. Please deliver this type of videos which really brain storm and change the thinking way of coding.
Hi John, i love this video. Learning algo on Leetcode is hard even with looking at the solution. However this video helped me understand 2 sum very easily. Thank you
I was stuck for hours looking on how to write the first line of code on such leetcode problems....leetcode can be intimidating but thanks for such content, it really helps!!....please do more especially in java
Great video, John! What sets you apart is that you have a very clear communication style, and you're very encouraging as well. I think that this LeetCode video showcases those skills really well, and it would be awesome if you made more in the future :)
Two sum was my first experience to how useful hash maps were. Started using them in all tasks where you need to look at every unique element of an array.
I'd love to see more videos about what you talked about at the last min of the video: "I never would have thought of that!". Your way of explaining the thought process is exactly what I'm looking for in these types of videos. I don't just want to see the solution to this or that coding problem, but the idea behind it. Please keep them coming!
Really good video, explaining the code was in-depth and at an appropriate level. Maybe a video on the time/space complexity? That was a hard concept for me starting out.
My freaking God John, that was the best explanation I've found so far on the internet. Sure there could be more ways but the fact that you are able to explain it so easily and also the way you communicate as a speaker is remarkable. Keep doing what you do buddy, and thanks a lot. ❤ from INDIA. I feel blessed that we have people like you working with JAVA.
this video is amazing!! thanks for all the explanation, please continue with this! Im using java to do these code challenges and your videos helps me a lot
Hey John, Thanks so much for your videos they have being really helpful to my java knowledge. I would love to see more videos from you on Arrays, OOP and Real life application of Arrays and OOP. Thanks a million. Big thumb 👍
Hi John, the way you explained is more clear and more precise so I suggest you do this kind of video more and make it a playlist for Leetcode easy problems, People who are new to Leetcode like me would appreciate more content like this.
Hey John please do more leetcode videos. I love how clear and precise your explanations are!! I was sad to only see the two videos in the playlist. Hope you’re doing great!!
Just started my Leetcode journey and this was the exact video I needed to feel more confident about trying more problem and being ok about not knowing the best answer or an answer at all. You thoroughly explained 2 ways of solving the Two Sum problem and reassured me that practicing more leetcode will sharpen my eye for finding solutions to coding problems. IMO this is a must watch for all first time leetcoders! Thank you John 🫶
I enjoy each and every bit of thing you do. when you write the code, when you feel something about the code and laugh, I laugh too. you are helping me and others who are just in the path of learning java in the best way possible. Huge respect for you Sir!! you just keep doing what you are doing, I am eager to learn a lot of things from you.
If you notice, he copies the code from intellijidea and pastes it into the leetcode space after deleting the existing code in the Leet code space. Where do you get the problem?
![เบิ้ล ปทุมราช - สาวสอง ( มีมี่ของอ้าย ) ft. ตาต้า,ต้องเต [OFFICIAL MV]](http://i.ytimg.com/vi/mqlMjnP08XI/mqdefault.jpg)
Please do this kind of videos more!
I second this
I third this
Fourth!
Fifth
This looks like an array, so I 5th this lol
Doing more these kinds of things is very helpful, especially how u approach them. Teachers normally tell us the optimal solution but how to get to that or how to come up with that solution is not normally taught to us.
Do more of these kind of videos because your thought process make me think in a different way than before.
Yes, more videos like this would be amazing because you don't only solve the challenges, but explain the thinking behind it.
well said sir ! Even I can understand the concepts quite easily and I'm not a native english speaker.
Thanks a lot John. Please start a Leetcode series, your way of explanation is flawless
I thought of your initial solution right away but would have NEVER thought of the better way. These types of videos are EXTREMELY helpful in reprogramming the way I look at a problem. Thank you!!
Comments like this help me understand that its ok that I couldnt come up with that second solution on my own. Thank you.
Love these algorithm video's personally, keep'em coming! Of course all your tutorials are also awesome- so I guess just keep up the good work!
honestly a weekly leetcode video like this would be so good. Please do more!
Please do this kind of videos.
It helps alot to understand the problem
Please, keep doing this leetcode content. There is not good leetcode videos in Java, so this is gold!
I definitely want more videos like this! You're an excellent teacher. I'm trying to get a job as a Java developer and I'm freshening up my knowledge. I will always come back to your videos. They are fun, interesting topics, easy explained and very helpful! 😃
If you struggle with finding a first job, try to look for testers, then get to automate tester, then you will be a perfect java coder because you know how stuff should work.
Requirements for junior tester are so little, it is easy to apply
More of these types of videos would be fantastic! Your explanations throughout all of your videos are incredible, and I just started tackling coding challenges and I've been struggling with how to even begin. Appreciate your channel so much!
Great solution.
You can decrease the memory footprint by not bothering storing the complement/index of values that are greater than the target as those would require negative numbers to achieve the target.
Well, the problems only states integers, so they might as well be negative, or?
@@tonypsilon_gaming3221 Fair enough.
But 1 question that I would ask is if negative numbers are possible in the source array.
But since this is an online test, which can be submitted multiple times, I'd assume as much and run my answer to see if it fails any test cases... If it passes all test cases, then I would add a comment explaining the optimization.
A playlist with videos like this would be phenomenal! Thank you for sharing these with us!
We want more leetcode questions! you're an expert in teaching. Thanks a lot.
really this is soo awesome because i just started doing leetcode and i wanted someone who can guide me and here you are like a angel :D
From what I know first solution is: O(n*(n-1)/2) and for the outer loop you should do: for (int i = 0; i < nums.length - 1; i++)
Of course it still can be simplified to O(n²) - but never really understand why. I mean it's quadratic, but still quite a reasonable difference to loop i and j from 0 to end. (about half the time of O(n²), which I think is still a difference, especially if it is longer, like from 20 mins to 10 mins)
All of your videos have been so incredibly helpful to a career changing CS student like myself! Leetcode has always seemed super intimidating but your teaching style really makes them seem doable. Please do more like this!
Was just solving this problem and your video came in. Thanks and would love to watch more videos on leet code problems.
Wow do more of these videos ! Love your explanation
Never thought about a solution like that before. This is a very useful tool to add to the tool box. Thanks!
Hi John , waiting for the next episode , it will really help to broaden the logical thinking .
I'm a java developer, but never imagined hashmap can be used in such a way.
I've to advocate that we do need more such stuff, @John.
In order to create a stash of solutions to common problems, I'd love to see more of such videos, taught by someone who really knows what he's doing and who can teach in a clear and straightforward manner. Thanks for sharing this knowledge.
Thank you John for taking the time in creating this video! Please do more of these videos as it teaches problem solving skills and how to walk through the creation of an algorithm. Thanks!
Great solution!
One small thing, i think we can reduce the runtime to 1ms by calculating list size out side the loop and do the iteration on calculated size ,otherwise, in each iteration in the loop java will take sime time to calculate the array size
int size= nums.length;
map=.....
for (int i = 0; i < size; i++) {
....
}
Do a lot more videos like this!!! I love The way you explain it, keep doing this
One of the best coding channels. VERY well explained. Cheers! You deserve way more subs.
That thing you said at the end... That makes me feel so much better about myself. I used to feel like there's something wrong with me, but it's natural, apparently!
Dude!! Thanks a lot for this video!! I was straggling with this same question in the AlgoExpert, and I couldn’t understood the Clément's explanation. You explained SO MUCH better, and for free... Please launch a course of Algorithms and Data Structure. I'll definitely pay for that.
As a mostly self taught dev, I really appreciate your content. It has helped me grasp concepts I've been struggling with for a very long time. Thank you!!
That's a great video! I had had struggle finding a solution for that kind of problems and that helps a lot. Thank you so much!
It took me a week to "sink in " but I solved my first leetcode with this video , thanks God this video Exist and Thank you John for creating such an amazing video .
Thank you for covering such problems and that too in detail. We usually don't get such insights when doing things alone. Please park some time for adding such videos regularly. Thank you
Yes more leet code/algo videos, there’s barely any good Java leet code videos on TH-cam. Mostly just python and JavaScript videos. Java is neglected on leet code.
I'm new to this channal. Before I saw this video I don't knew what is really hashmap is but after seeing this..... Nothing to say.
This video is really helpful.
Thank's for creating this awesome video.
Thanks for the encouragement at the end. My solution is close but not quite optimal. It's O(n) space complexity but O(2n) time complexity. I felt bad about not thinking about the hashmap solution until you gave your encouraging words at the end! Thanks man 🥺
Thank you. This was super interesting (to me, anyway). Please give us a few of these every now and then - I'm not asking you to make it exclusive, but it was fun.
please make more of these exercises! This is a good way to learn and practice coding
Wow !
Really a brilliant solution using a Map. 😇
Thanks for this video John. I learnt a new technique today. 👍
Really like the way you have presented the logic and would like to see more of these kind of videos.
Plz do this more often I'm learning java so it's very helpful on how to approach leetcode problems. Thanks.
This solution is amazing. We would love to see more questions of this complexity
I really needed to hear that last bit in the end. im a 2nd yr cs student and ab to do my first technical test for an internship n i find them very hard and even thought of dropping out lol. so thank you
Would definitely like to see more challenges! Never would've thought about using a hashmap and like you said, one more thing I've learnt. Thanks a million. You're a great teacher!
Thanks John, this puts a smile on my face. Hope to see more of this
Can you please do more of these? Your explanation was so clear and to the point, I wish there was more!
Simply amazing channel. Gives me so much confidence to keep learning and not to give up.
Please do these kind of videos.. because of your great explanation about hashmap now i understood it.. Before i know what is a map, set but i don't know how they actually work..now i know
Thankyou
Please we need such kind more questions! Appreciated!
Please make more videos like this, your explanation is just amazing💞. I am grateful to have people like you delivering high quality content free 🙏🙏🙏
9:44 The solution will return [2, 2] for a target off 8 which is incorrect since the same element is used twice.
The code for the "i" should be for (int i = 0; i < nums.length - 1; i++) {...} For the i, j loop version.
I really appreciate the message you start to give at 21:57 - I have been feeling very discouraged as of late trying to sharpen my problem solving skills and it was very comforting to hear that. Thank you!
I have to agree with the majority of the other comments - your explanations of algorithms for solving LeetCode solutions (well, in general good software algorithms) are some of the clearest I've seen. This is probably going to be a new subcategory of videos that you might not have planned to do, but I can see there's so much interest you have no choice but to do them! (Please?)
Thanks a lot for this clear explanation! Please, do more tutorials for LeetCode exercises!🙏
I had to rewatch the last section as you suggested to finally get it, thanks again John. You are the man.
Im so grateful you are doing this.
You are one amazing teacher. It’s so easy to understand code with your explanations.
Very very grateful.
Yes.. Nice. Coding is not just getting the correct result. But it also getting the result in correct/optimal way. Please deliver this type of videos which really brain storm and change the thinking way of coding.
OMG!!!!! man how can you be so good at teaching ??? you just made my day. please keep the videos coming 🙂
I don't get it, why people don't subscribe and like this guy's channel and videos. He is the best.
Hi John, i love this video. Learning algo on Leetcode is hard even with looking at the solution. However this video helped me understand 2 sum very easily. Thank you
Please do this kind of video more and more! your explanation is so easy to understand. I got the concept in the first watch only.
thank you solving problem with deep details, we having mostly trouble to understand , the way how you explain is highly catchable
Well, i think i can watch these kind of videos whole day without getting bored. Well done. Just perfect.
You have a brilliant mind, that’s so simple solution and very smart
This did kind of blow my mind ngl.
I would've never thought of this solution to the problem.
Now I wonder where else this method might be applicable.
Thank you for this video. Please do more of the Leetcode problems. Thank you.
please do more videos like this. your channel is more helpful for beginners too.
Love the way you teach and present the content in most simplest way, It would be great to see DSA and System design courses from you.
I was stuck for hours looking on how to write the first line of code on such leetcode problems....leetcode can be intimidating but thanks for such content, it really helps!!....please do more especially in java
Great video, John! What sets you apart is that you have a very clear communication style, and you're very encouraging as well. I think that this LeetCode video showcases those skills really well, and it would be awesome if you made more in the future :)
Need more videos like this John 😋
So happy i found your channel...😎 premium value ✌️✌️✌️
First thanks for the video. Please do this kind of video more! It's helped me a lot.
you are awesome man! You've given me a new way to face problems like these! Thank you.
Please post this kind of videos more. I like the way you explaining the details by going into the deep. I am waiting😋
Two sum was my first experience to how useful hash maps were. Started using them in all tasks where you need to look at every unique element of an array.
I'd love to see more videos about what you talked about at the last min of the video: "I never would have thought of that!".
Your way of explaining the thought process is exactly what I'm looking for in these types of videos. I don't just want to see the solution to this or that coding problem, but the idea behind it.
Please keep them coming!
Please make more of these videos. This video was very well explained.
Thanks, I plan to!
Really good video, explaining the code was in-depth and at an appropriate level. Maybe a video on the time/space complexity? That was a hard concept for me starting out.
My freaking God John, that was the best explanation I've found so far on the internet. Sure there could be more ways but the fact that you are able to explain it so easily and also the way you communicate as a speaker is remarkable.
Keep doing what you do buddy, and thanks a lot. ❤ from INDIA. I feel blessed that we have people like you working with JAVA.
Thanks John. This was very helpful. Please keep adding more of these kind of videos.
Glad it was helpful, I'm planning to!
Please do more. I would like to learn and see how you approach the problem, why you think and how you think.thank you
please stop, you have some very good java vids, super useful. for any leetcode question you can find million solutions.
this video is amazing!! thanks for all the explanation, please continue with this! Im using java to do these code challenges and your videos helps me a lot
Hey John,
Thanks so much for your videos they have being really helpful to my java knowledge.
I would love to see more videos from you on Arrays, OOP and Real life application of Arrays and OOP.
Thanks a million.
Big thumb 👍
Please do more like this. this is really awesome
Thank you, I was struggling on how to optimize my solution in C using just One for loop.
Amazing!! I started enjoying java due to your videos :)
Yes
Please add more videos of leetcode problems
Hi John, the way you explained is more clear and more precise so I suggest you do this kind of video more and make it a playlist for Leetcode easy problems, People who are new to Leetcode like me would appreciate more content like this.
Hey John please do more leetcode videos. I love how clear and precise your explanations are!! I was sad to only see the two videos in the playlist. Hope you’re doing great!!
Thanks for the video. Theres not enough of these out there
Amazing video John, thanks!!! I would love a Java Leetcode series :)
Just started my Leetcode journey and this was the exact video I needed to feel more confident about trying more problem and being ok about not knowing the best answer or an answer at all. You thoroughly explained 2 ways of solving the Two Sum problem and reassured me that practicing more leetcode will sharpen my eye for finding solutions to coding problems. IMO this is a must watch for all first time leetcoders! Thank you John 🫶
I enjoy each and every bit of thing you do. when you write the code, when you feel something about the code and laugh, I laugh too. you are helping me and others who are just in the path of learning java in the best way possible. Huge respect for you Sir!! you just keep doing what you are doing, I am eager to learn a lot of things from you.
Hey John! Thank you so much. Your simplifications make it so much easier. keep going and keep growing.
I am sorry to disturb you , do you know how he could copy the problem to intillij directly ?
If you notice, he copies the code from intellijidea and pastes it into the leetcode space after deleting the existing code in the Leet code space. Where do you get the problem?
@@mislam2565 What i meant was how he could move the problem _at first _to intellij idea , specifically at 3:17 .
@@user-mh7bq5gx9c He doesn’t show it there, but we need to create new java class, name it ‘Solution’ and then copy the code. Hope it helps
@@mislam2565
Thanks
Dude this video is brilliant and excellent! Not just the solution, the explanations and the speech at the end as well. Thank you!
Please do more of these leetcode videos!
The most recent video is another one!
thanks for your thorough explanation of the hash map! I understand it so much better now!