1018_90%_100%

class Solution {
public:
    vector<bool> prefixesDivBy5(vector<int>& A) {
        vector<bool> result;
        if(A.size() < 1)
            return result;
        long long num = 0;
        int k = 0;
        for(int i = 0; i < A.size(); i ++){
            num = k * 2 + A[i];
            result.push_back(num%5<1);
            k = num % 10;
            //cout<<num<<endl;
        }
        return result;
    }
};