How to exchange two variables without using a third

skie_knite007 · 03-11-2005, 04:29 AM

Is it possible to exchage two variables without using temp?
(in C)

how can it be done.....!!!!!!!!!!

idefinehell · 03-11-2005, 04:42 AM

a,b be the two variables
(I)
temp=a;
a=b;
b=temp;

using an extra variable

and with out using an extra variable
(II)
a=a+b;
b=a-b;
a=a-b;

There r many ways 2 swap values of two variables
Hope this helps :-)

nulldevice · 03-11-2005, 04:48 AM

a^=b^=c^=a
but all these will work for integers only. when u say variable it has a larger context

Hko · 03-11-2005, 05:09 AM

Quote:

Originally posted by nulldevice
a^=b^=c^=a

But that still uses an extra variable: "c"....

This should work:

Code:

a = a^b;
b = a^b;
a = a^b;