leetcode 709. 转换成小写字母

题解

class Solution {
public:
    string toLowerCase(string s) {
        string ans;
        for (int i = 0; i < s.size(); i++) {
            if (s[i] >= 'A' && s[i] <= 'Z') {
                s[i] += 32;
            }
            ans += s[i];
        }
        return ans;
    }
};