Swap Values Without Using Third Variable Program using CPP

Source Code

#include <iostream>

using namespace std;

int main(int argc, char** argv) {
    
    // Variable Declaration for input
    int a,b;

    // Taking input in variables  
    cout<<"Enter First Number: ";
    cin>>a;
    cout<<"Enter Second Number: ";
    cin>>b;
    
    // Swapping values
    a = a + b;
    b = a - b;
    a = a - b;
    
    // Values after swapping
    cout<<" First Number: "<<a;
    cout<<"\n Second Number: "<<b;
    
    return 0;
}

Output

Working

First of all two variables a and b are declared of type int. After this we take input in these variables using cin statement. Then swap these values using the following procedure.

• Get sum of both variables and assign it to first variable says a.
• Then deduct (subtract) value of variable b from total value (containing a).
• This deduction will result actual value of a (because total contains sum of both a and b).
• Now again we will deduct b (which now contains value of a after first deduction) from a.
• This will result in interchange value of these two variables without using third variable.