3675. Minimum Operations to Transform String

You are given a string s consisting only of lowercase English letters.

You can perform the following operation any number of times (including zero):

• Choose any character c in the string and replace every occurrence of c with the next lowercase letter in the English alphabet.

Return the minimum number of operations required to transform s into a string consisting of only 'a' characters.

Note:Consider the alphabet as circular, thus 'a' comes after 'z'.

class Solution {
public:
    int minOperations(string s) {
        int res = 0;
        for(auto& ch : s) {
            if(ch != 'a') res = max(res, 26 - ch + 'a');
        }
        return res;
    }
};