Leetcode (27): Remove Element

https://leetcode.com/problems/remove-element/

Given an array and a value, remove all instances of that value in place and return the new length.

The order of elements can be changed. It doesn ' t matter what are you leave beyond the new length.

Ideas:

Because you can change the order of elements, you only need to replace the last non-Val element with the most front-end Val, and the front and back two pointers move at the same time until they meet.

AC Code:

1 classSolution {2  Public:3     intRemoveelement (vector<int>& Nums,intval) {4         intI=0, N=nums.size ()-1;5         if(n<0)6             return 0;7          while(nums[n]==val)8n--;9         if(n<0)Ten             return 0; One          while(i<N) { A              while(nums[n]==val) { -n--; -             } the             if(i>N) -                  Break; -             if(nums[i]==val) { -nums[i]=Nums[n]; +n--; -             } +i++; A         } at          while(nums[n]==val) { -n--; -             } -         returnn+1; -     } -};

Leetcode (27): Remove Element