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 }