LeetCode 1018. Binary Prefix Divisible By 5

class Solution {
public:
    vector<bool> prefixesDivBy5(vector<int>& A) {
        vector<bool> ans;
        int mask = 0;
        for (const int i : A) {
            mask = ((mask << 1) + i) % 5;
            ans.emplace_back(mask == 0);
        }
        return ans;
    }
};