1018. 可被 5 整除的二进制前缀
二进制的题总是这么神奇
class Solution {
public:
vector<bool> prefixesDivBy5(vector<int> &A) {
int num = 0;
vector<bool> res;
for (int i = 0; i < A.size(); i++) {
num = ((num << 1) + A[i]) % 5;
if (num == 0 || num == 5)
res.push_back(true);
else
res.push_back(false);
};
return res;
}
};
