leetcode

3228.cpp (429B)

 class Solution {
   public:
     int maxOperations(const string &s) const {
         const int n = size(s);
         int res = 0, count = 0;
 
         for (int i = 0; i < n;) {
             const int start = i;
 
             while (i < n && s[i] == s[start])
                 i++;
 
             if (s[start] == '0')
                 res += count;
             else
                 count += i - start;
         }
         return res;
     }
 };