LeetCode Remove Element

题目：

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 you leave beyond the new length.

class Solution {
public:
    //找到元素后，从数组结尾抽取数值覆盖
    int removeElement(int A[], int n, int elem) {
        int k = 0;
        for(int i = 0; i < n-k; i++) {
            if(A[i] == elem) {
                if(i == n-1-k) {
                    k++;
                    break;
                }
                A[i] = A[n-1-k];
                k++;
                i--;
            }
        }
        return n-k;
    }
};