Sort Colors

 

 

Day 1 : SDE Sheet

 https://leetcode.com/problems/sort-colors/submissions/

 https://www.geeksforgeeks.org/sort-an-array-of-0s-1s-and-2s/

class Solution {
public:
    void sortColors(vector<int>& nums) {
        //Dutch National Flag Algorithm
        int low=0;
        int high=nums.size()-1;
        int mid=0;
        while(mid<=high){
            if(nums[mid]==0){
                swap(nums[mid],nums[low]);
                low++;
                mid++;
            }
            else if(nums[mid]==1){
                mid++;
            }
            else if(nums[mid]==2){
                swap(nums[mid],nums[high]);
                high--;
            }
        }
       
    }
};