SWAP TWO NUMBERS WITH OUT USING THIRD VARIABLE

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b;

clrscr();

printf("enter the 1st value :-\n");

scanf("%d",&a);

printf("Enter the 2nd value :-\n");

scanf("%d",&b);

printf("\nBefore swap the value of a=%d and b=%d\n",a,b);

b=a+b;

a=b-a;

b=b-a;

printf("After swap the value of a=%d and b=%d\n",a,b);

getch();

}