swap two variables without using a third variable as an intermediary position

Question

Write a program to swap two variables without using a third variable as an intermediary position.

a=2; b=3;
a=a*b; // 6
b=a/b; // 2
a=a/b; // 3
a=3 and b=2

????is it true,,,i have errors in it

Homework? You can look up a solution on the web. The classic one uses xor. — Ray Toal, Mar 06 '12 at 09:13
can you be a little more specific about what your question/errors are? — Cameron, Mar 06 '12 at 09:14

score 1 · Answer 1 · answered Mar 06 '12 at 09:15

1

better use reversible operators without "singularities". Such as +, - (assuming integer wraparounds are ok.

And, of course, the winner is XOR.

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

answered Mar 06 '12 at 09:15

valdo

score 0 · Answer 2 · answered Mar 06 '12 at 09:13

0

What happens if b or a is zero? If neither is zero and you do not get overflow of the type your code will work.

answered Mar 06 '12 at 09:13

Boris Strandjev

2 Answers2