SWAPPING WITH OUT TEMP VARIABLE

 int swap(int *a,int *b)

{

 *a=*a+*b;*b=*a-*b;*a=*a-*b;

}

main()

{

 int x=10,y=20;

 swap(&x,&y);

 printf("x= %d y = %d\n",x,y);

}