3922. Minimum Flips to Make Binary String Coherent

You are given a binary string s.

A string is considered coherent if it does not contain "011" or "110" as subsequences.

In one operation, you can flip any character in s ('0' to '1' or '1' to '0').

Return an integer denoting the minimum number of operations required to make s coherent.

class Solution {
public:
    int minFlips(string s) {
        int res = INT_MAX, one = count(begin(s), end(s), '1'), n = s.length();
        if(n <= 2) return 0;
        res = min(one, n - one);
        if(one) res = min(res, one - 1);
        if(s[0] == '1') one--;
        if(s[n-1] == '1') one--;
        res = min(res, one);
        return res;
    }
};