3884. First Matching Character From Both Ends

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

Return the smallest index i such that s[i] == s[n - i - 1].

If no such index exists, return -1.

class Solution {
public:
    int firstMatchingIndex(string s) {
        int n = s.length();
        for(int i = 0; i < n; i++) {
            if(s[i] == s[n-i-1]) return i;
        }
        return -1;
    }
};