Swapping Two Numbers Using C

# include <stdio.h>
# include <conio.h>
void main()
{
int a, b ;
clrscr() ;
printf("Enter two numbers : ") ;
scanf("%d %d", &a, &b) ;
printf("\nBefore swapping : \n\n") ;
printf("a = %d \t b = %d", a, b) ;
a = a + b ;
b = a - b ;
a = a - b ;
printf("\n\nAfter swapping : \n\n") ;
printf("a = %d \t b = %d", a, b) ;
getch() ;
}
RUN 1 :
~~~~~~~
Enter two numbers : 10 20
Before swapping :
a = 10 b = 20
After swapping :
a = 20 b = 10