LeetCode 0027 - Remove Element

Given nums = [3,2,2,3], val = 3,

Your function should return length = 2, with the first two elements of nums being 2.

class Solution {
public:
    int removeElement(vector<int>& nums, int val) {
        int cnt = 0;
        for(int i = 0 ; i < nums.size() ; ++i) {
            if(nums[i] == val)
                cnt++;
            else
                nums[i-cnt] = nums[i];
        }
        return nums.size()-cnt;
    }
};