https://www.bilibili.com/video/BV1vv411a7r5

从答案出发 枚举加效验
class Solution {
public:
    int slove(const string& s, int v)
    {
        int cnt = 0;
        for(int i=0;i<s.size();i++,v=1-v)
        {
            if(s[i]-'0'!=v) cnt++;
        }
        return cnt;
    }
    int minOperations(string s) {

        int res = INT_MAX;

        //目标串 010101.....
        res = min(res, slove(s,0));
        //目标串是101010....
        res = min(res, slove(s,1)); 

        return res;
    }
};