Program to swap two numbers without using third variable.

/*Serial No.21     [swami142.cpp]*/

#include<stdio.h>
#include<conio.h>
void main()
{
int a,b;
clrscr();
printf("Enter the first no. a=");
scanf("%d",&a);
printf("Enter the second no. b=");
scanf("%d",&b);
a=a+b;
b=a-b;
a=a-b;
printf("After swaping numbers are:\na=%d\tb=%d",a,b);
getch();
}