Write a function that takes a string as input and returns the string reversed.
Example:
Given s = "hello", return "olleh".
char* reverseString(char* s) { int len = strlen(s); for (int i=0; i<len/2; i++) { char t = s[i]; s[i] = s[len-i-1]; s[len-i-1] = t; } return s; }
原文：http://www.cnblogs.com/wxisme/p/5940663.html