wap to swap the two number without using 3rd variable in c language

 wap to swap the two number without using 3rd variable in c language 

Program:-

#include<stdio.h>

#include<conio.h>

main()

{

int a,b,c;

clrscr();

printf("enter the value for a");

scanf("%d",&a);

printf("enter the value for b");

scanf("%d", & b);

printf("before swaping value of a=%d and b=%d",a,b);

a=a+b;

b=a-b;

a=a-b;

printf("after swaping value of a=%d and b=%d",a,b);

getch();

}