第一题(AC): 一次可以变2个,将字符串变为全0或全1 思路:暴力 class Solution { public: int minOperations(string str) { int len = str.length(); // all to 0 int ans0 = 0; for (int i = 0; i < len; ++i) { if (str[i] == '1') { ++ans0; ++i; ...