Swapping of numbers using call-by-reference program in c

#include<stdio.h>
 
void main()


{


  int a=10,b=50;


  void swap(int *,int *);


  clrscr();


  printf("Before Swapping: %d %d\n",a,b);


  swap(&a,&b);


  printf("After Swapping: %d %d\n",a,b);


}


void swap(int *a,int *b)


{
  int t;

  t=*a;


  *a=*b;


  *b=t;


}

Output :

Before Swapping: 10 50

After Swapping: 50 10