力扣 2697. 字典序最小回文串

题目来源：https://leetcode.cn/problems/lexicographically-smallest-palindrome/

 C++题解：从两端往中间判断，不同时则用字典序小的替换字典序大的。

class Solution {
public:
    string makeSmallestPalindrome(string s) {
        int len = s.size();
        for(int ii = 0; ii < len/2; ii++) {
            if(s[ii] != s[len - ii - 1]) {
                if(s[ii] < s[len - ii - 1]) s[len - ii - 1] = s[ii];
                else s[ii] = s[len - ii - 1];
            }
        }
        return s;
    }
};