majority_number_in_an_array.cpp

class Solution {
public:
    int majorityElement(vector<int> &num) {
        int cnt = 0;
        for(int i=0; i<num.size(); i++){
            if(cnt == 0){
                maj = num[i];
                cnt++;
            }
            else if(maj == num[i])
                if(cnt > n/2) return maj;
            else cnt--;
        }
        return maj;
    }
};