LeetCode "Majority Element"

Really interesting O(n) problem. Just like playing.. so actually working on algorithm problems is like playing games!

class Solution {
public:
    int majorityElement(vector<int> &num) 
    {
        int ret = num[0];
        int cnt = 1;
        for (int i = 1; i < num.size(); i ++)
        {
            if (cnt == 0) ret = num[i];
            if(num[i] == ret)    cnt ++;
            else                cnt--;
        }
        return ret;
    }
};