Program in C to implement the parameter passing technique in function (call by value and call by reference)

#include<stdio.h>
#include<conio.h>
void vswap(int,int);
void rswap(int*,int*);
void main()
{
int a,b,c;
clrscr();
printf("\nEnter the value of a and b\n");
scanf("%d%d",&a,&b);
while(1)
{
printf("\nEnter your choice:\n1.For call by value");
printf("\n2.For call by Referance\n3.Exit\n");
scanf("%d",&c);
switch(c)
{
case 1:
printf("\nb4 swap the value of a and b is:%d %d",a,b);
vswap(a,b);
printf("\nafter swap the value of a and b is:%d %d",a,b);
break;
case 2:
printf("\nb4 swap the value of a and b is:%d %d",a,b);
rswap(&a,&b);
printf("\nafter swap the value of a and b is:%d %d",a,b);
break;
case 3:
printf("\nbye.. press any key to continue...");
getch();
exit(0);
default:
printf("Not valid choice");
}
}
}
void vswap(int x,int y)
{
int temp;
temp=x;
x=y;
y=temp;
}
void rswap(int *x,int *y)
{
int temp;
temp=*x;
*x=*y;
*y=temp;
}

Output: