StrRevert

#include <iostream>

int main() {
  const char* c = "hi";
  int n = 2;

  char* s = new char[n];

  for (int i = 0; i < n; ++i)
    s[n - 1 - i] = c[i];
  std::cout << s;

  delete[] s;
  return 0;
}