#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,*ptr1,*ptr2,temp;
printf("enter the values ");
scanf("%d%d",&a,&b);
ptr1=&a;
ptr2=&b;
temp=(*ptr1);
*ptr=(*ptr2);
*ptr2=temp;
printf("\n now the values are a=%d b=%d ",a,b);
getch();
}


thank u

#include<iostream.h>
#include<conio.h>
void main()
{
int a,b;

void swap(int *,int *);  //Functioin Prototype
clrscr();
cout<<"\nEnter the number::\n";
cin>>a>>b;
cout<<"\nValues before INterchange are \na=<<" and \nb="<<b;

swap(&a,&b);   //Functiion Calling

cout<<"\nValues after interchange\na=<<" and \nb="<<b;

getch();
}

void swap(int *a,int *b)    //Function Defintioon
int temp;
temp=*a;
*a=*b;
*b=temp;

}




Thanks friends if any mistake pls coorect it by again urs 
answer

#include<stdio.h>
main()
{
int *p,*q;
*p=10;
*q=20
void swap(int &p,int &q);
}
void swap(int *x,int *y);
{
int *tmp;
*tmp=*x;
*x=*y;
*y=*x;
printf("%d,%d",*x,*y);
}