Sort Colors (LeetCode 75) | Dutch National Flag Problem | Full Solution with Visuals and Animations

Yay, someone I can understand

good

Underrated!

Thank you for providing such fantastic content

Thank you

Your the best bro. The problem seems so easy with the way you explain it. Thanks again. Also this is my solution in python based on your approach

class Solution:
def sortColors(self, nums: List[int]) -> None:
"""
Do not return anything, modify nums in-place instead.
"""

start = 0
middle = 0
end = len(nums ) - 1

while middle <= end:

if nums[middle] == 0:
nums[start], nums[middle] = nums[middle], nums[start]
start += 1
middle += 1

elif nums[middle] == 1:
middle += 1

elif nums[middle] == 2:
nums[end], nums[middle] = nums[middle], nums[end]
end -= 1

Your the best bro. The problem seems so easy with the way you explain it. Thanks again. Also this is my solution in python based on your approac

very good explanation! keep up the good work

Why not just count zeroes and ones and refill the array in place? 😂

Best solution I've seen for this problem. This channel is so underrated.

your explanations are really amazing. In fact, best so far :) Please make more videos :)

why we are not incrementing mid when it is arr[mid] is 2?

Thanks

Thank you soo much ❤❤

Thank you, ploblem solved. love you
😁

i used selection sort

Great explaination! But I noticed one thing, in the first example, first swap is wrong as middle was at 0, so swap between start and middle should take place and start and middle should move and not between middle and end i.e 0 and 2 what you did because middle was not at 2.

💯❤

sir, I actually used in-built sort function, in leetcode ie. sort(nums.begin(),nums.end()), and it said said, u beat 100% users with c++. Can we do this or not???

why don't we just loop through the entire array and count the 0's and 1's in seperate variables, then loop the array again and replace number of 0, 1, 2 in that order.

VERY NICE EXPLANATION WITH CLARITY . THANKS BHAIYA .

Great explanation, good work

Picture perfect mate!
Thanks.

best explanation Sir! I didn't watch the coding part before solving the problem. So I implemented it using if-else statements.After solving, I watched the last part. I found out you wrote it using switch cases. Understanding both versions make me confident in coding

Java Solution (Beats 100 %)
class Solution {
public void sortColors(int[] nums) {
int n = nums.length ;
int[] arr = new int[3] ;
int element = 0 ;
for(int i = 0 ; i < n ; i++){
element = nums[i] ;
arr[element]++ ;
}
int count = 0 ;
int k = 0 ;
for(int i = 0 ; i<3 ; i++){
count = arr[i] ;
while(count > 0){
nums[k] = i ;
k++ ;
count-- ;
}
}
}
}

c++
class Solution {
public:
void sortColors(vector<int>& nums) {
int start = 0;
int middle = 0;
int end = nums.size() - 1;

while (middle <= end) {
if (nums[middle] == 0) {
swap(nums[start], nums[middle]);
start++;
middle++;
} else if (nums[middle] == 1) {
middle++;
} else if (nums[middle] == 2) {
swap(nums[middle], nums[end]);
end--;
}
}
}

void swap(int& a, int& b) {
int temp = a;
a = b;
b = temp;
}
};

❤

Man that’s the best explanation. I saw the coded solution for this problem which is same as yours but couldn’t wrap my head around it. Now I got it! Thank you!

Thanks man this helped me a lot, loved your energy throughout the problem.

YOU MADE IT THE SIMPLEST TO UNDERSTAND WITHOUT COMPLICATING THINGS!!!!! HAT'S OFF TO YOU!

Too difficult to understand what he says because of his accent.

This is better than strivers i watched him then i watched you had a strongn feeling this would be good🎉

you are super good

Best solution I've seen for this problem. This channel is so underrated.

really very good explanation. you made it so easy

bhai whai is vailya

OP

Thanks Brother❤

GREAT VIDEO

wow. such a simple and wonderful solution

Hi Nikhil!! I am so glad to find this channel. The presentation and the way you explain things in a simple and easy-to-understand manner are awesome. Last but not least, the dry run and the explanation of the code are what I have been looking for so long. I finally found your channel. Thanks a ton, brother.

Wow wow. I watched tons of video on DNF algoritm, I didn't understood whay they are saying. You explaind it excellently.

thanks a tonn very clear explanation !! beginner friendly

Most recommended Channel for DSA Question Solving.

why XOR swapping is not working here ???????????????????????????

Nice video...thanku sir

Thanks Nikhil sir, you really made the concept easy!

Why did you make a special function swap ??

This is nice explanation unlike others who tried to explain the algorithm with out explaining the logic