Swap without using extra variable (C++)

swapNoTemp.cpp

#include <iostream>

using namespace std;

/**
* Swap the parameters.
* @param a The first parameter.
* @param a The second parameter.
*/
void swap(int& a, int& b)
{
    int temp = a;
    a = b;
    b = temp;
}

/**
* Swap the parameters without a temp variable.
* Warning! Susceptible to overflow/underflow.
* @param a The first parameter.
* @param a The second parameter.
*/
void swapNoTemp(int& a, int& b)
{
    a -= b;
    b += a;// b gets the original value of a
    a = (b - a);// a gets the original value of b
}

int main() 
{
    int a = 100;
    int b = 500;
    cout << "a = " << a << " b = " << b << endl;
    swapNoTemp(a, b);
    cout << "a = " << a << " b = " << b << endl;
    return 0;
}

This code was developed by me, G. Samaras.

Notice, that I used as little C++ as possible, so that one can easy interchange between C and C++.
Have questions about this code? Comments? Did you find a bug? Let me know! 😀
Page created by G. (George) Samaras (DIT)