【leetcode】1018. 可被 5 整除的二进制前缀

利用取余的方法防止数值越界

class Solution {
     public:   vector<bool> prefixesDivBy5(vector<int>& A) {
        
    vector<bool> answer;   
     int sum = 0;     
  for(int i = 0; i<A.size(); ++i)        {
           
 sum = 2*(sum + A[i]);       
 sum %= 5;        
  if(sum == 0)   {
           
   answer.push_back(true);         
  }       
  else    {
                
 answer.push_back(false);       
  }
  }     
 return answer;
}
};