CC1.2.c

/*
 *1.2 Implement a function void reverse(char* str) in C or C++ which reverses a null-terminated string.
**/
void reverse(char* str) {
  char* end = str;
  if(str) {
    while(*end) {
      end++;
    }
    end--;
    char tmp;
    while(str<end) {
      tmp = *str;
      *str++ = *end;
      *end-- = tmp;
    }
  }
}