#include <stdio.h>


void swap(int *x, int *y) {

  int t = *x;
  *x = *y;
  *y = t;
}
   
void print_int_array(char* name, int* array, int size){

  int i;

  printf("%s:", name);
  for(i= 0; i<size; i++)
    printf(" %i", array[i]);
  printf("\n");
}

int main(){
  

  int a[]= {1, 2, 3, 4};
  int b[]= {5, 6, 7, 8};

  print_int_array("a", a, 4);
  print_int_array("b", b, 4);

  int i;
  for(i=0; i<4; i++)
    swap(&a[i], &b[i]);

  print_int_array("a", a, 4);
  print_int_array("b", b, 4);
}