#include <stdio.h>

void troca(int *end_x, int *end_y) {
  int aux;

  aux = *end_x;
  *end_x = *end_y;
  *end_y = aux;
}

int main() {
  int x = 100, y = 200;

  troca(&x, &y);
  printf("x = %d, y = %d\n", x, y);
  
  return 0;
}