27. Remove Element

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)
            {
                nums[cnt++] = nums[i];
            }
        }
        return cnt;
    }
};

• T: $O(N)$
• S: $O(1)$