LeetCode刷题：709.To Lower Case

709. To Lower Case

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase.
Example 1:

Input: “Hello”

Output: “hello”

Example 2:

Input: “here”

Output: “here”

Example 3:

Input: “LOVELY”

Output: “lovely”

解题思路：

利用C++ tolower()函数；

解答：

class Solution {
public:
    string toLowerCase(string str) {
        for(auto &letter : str)
        {
            letter = tolower(letter);
        }
        return str;
    }
};