Swapping variables in C

This is a post on NNF by user viper and edited by other users.I have posted it here because I found it impressive although I haven't compiled it somebody plz. ....


normally to swap a n b you would

void swap(int a, int b)
{
int temp;

printf("val of a =%d and val of b=%d",a,b);
temp=a;
a=b;
b=temp;
printf("val of a =%d and val of b=%d",a,b);
}

u can do this without allocating the variable temp as

void swap(int a, int b)
{
printf("val of a =%d and val of b=%d",a,b);
a= a + b;
b= a - b;
a= a - b;
printf("val of a =%d and val of b=%d",a,b);
}