[leetcode]Two Pointers-344. Reverse String

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

Example:
Given s = "hello", return "olleh".

char* reverseString(char* s) {
2     assert(s != NULL);
3     int len= strlen(s)-1;
4     char* tmp = (char *)malloc(len+2);
5     for(int i = len; i>=0; --i)
6         tmp[len-i] = s[i];
7     tmp[len+1]='\0';
8     return tmp;
9 }