leetcode-Reverse String

反转字符串，

Write a function that takes a string as input and returns the string reversed.

Example:
Given s = “hello”, return “olleh”.

		string reverseString(string s) 
		{
			if (s.size() == 0)return "";

			int x = 0;
			int y = s.size() - 1;

			for (int i = 0; i < s.size() / 2; i++,x++,y--)
			{
			    s[x] = s[x] ^ s[y];
				s[y] = s[x] ^ s[y];
				s[x] = s[x] ^ s[y];;

			}
			return s;
		}