题目描述：
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：
还是直接看代码。
代码：
1 char* toLowerCase(char* str) { 2 for (int i = 0; str[i] != ' '; ++i) { 3 if (str[i] >= 'A' && str[i] <= 'Z') { 4 str[i] = str[i] - ('A' - 'a'); 5 } 6 } 7 return str; 8 }