C Program to swap two numbers without third           variable

1. #include<stdio.h>
2. #include<conio.h>  
3.  void  main()    
4. {    
5. int a, b;
6. clrscr();      
7. printf(" enter the  two number for swapping"); 
8. scanf("%d%d",&a,%b);     
9. a=a+b;   
10. b=a-b;   
11. a=a-b;  
12. printf("\nAfter swap a=%d b=%d",a,b);    
13. getch();  
14. }