swap 2 numbers without arithmatic operations, pointers & Temp

[vijay]

Hi friends

I need an algorithm to swap two variables without using temporary variables,arithmatic operators and pointers. Please tell your logic to solve this problem.

[sowmya571]

hello







#include <iostream>

using namespace std;

int main()
{
float a = 1.7;
float b = -7.1;

cout << "a = " << a << " b = " << b << endl;
// swap a with b
a = a + b;
b = a - b;
a = a - b;
cout << "after swapping a with b:" << endl;
cout << "a = " << a << " b = " << b << endl;

cin.get(); // wait
return EXIT_SUCCESS;
}

this is the logic of simple program

bye

[sowmya571]

hello



the program given will help u to decide the algorithem okey



so BUILD IT ON UR OWN very easy . try it out im sure u will get



bye[img]smileys/smiley1.gif[/img]

[Sankar]

Hey use these lines intead of those given by sowmya

think ^ denotes XOR

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

you can decode these steps as

1. a = a ^ b -> a has both the values of a and b.

2. b = b ^ a -> this is equivalent to b = b ^ (a ^ b). XORing same values results in 1. So the value a is set to b.

3. a = a ^ b -> this is equivalent to a = (a ^ b) ^ (a). So the value b is set to a.

Note : the values betwwen ( and ) gives the value replaced for that variable.

[sk_kireeti]

Thanks Sankar... I was really searching for this logic.

[arunabha2003]

Great job dude.......


Rock on..............


[img]smileys/smiley1.gif[/img][img]smileys/smiley17.gif[/img][img]smileys/smiley2.gif[/img]

[sowmya571]

hello



Ya this is the logic XOR operator will do it .. Gud work Sarkar!



bye



sowmya