﻿ C++ : Swap two variables not using third variable

# C++ Exercises: Swap the values of two variables not using third variable

## C++ Basic: Exercise-48 with Solution

Write a C++ program that swaps two variables without using a third variable.

Visual Presentation:

Sample Solution:

C++ Code :

#include <iostream> // Including the input-output stream header file

using namespace std; // Using the standard namespace

int main() // Start of the main function
{
cout << "\n\n Swap two numbers without using third variable:\n"; // Displaying the purpose of the program
cout << "---------------------------------------------------\n";

int num1, num2, temp; // Declaring three integer variables to hold numbers

cout << " Input 1st number : "; // Prompting the user to input the first number
cin >> num1; // Taking the first number as input from the user

cout << " Input 2nd number : "; // Prompting the user to input the second number
cin >> num2; // Taking the second number as input from the user

num2 = num2 + num1; // Swapping logic: adding both numbers and storing the result in num2
num1 = num2 - num1; // Swapping logic: subtracting the original num1 from the updated num2 and storing the result in num1
num2 = num2 - num1; // Swapping logic: subtracting the updated num1 from the updated num2 and storing the result in num2

// Displaying the swapped numbers
cout << " After swapping the 1st number is : " << num1 << "\n";
cout << " After swapping the 2nd number is : " << num2 << "\n\n";
}

Sample Output:

Swap two numbers without using third variable:
---------------------------------------------------
Input 1st number : 25
Input 2nd number : 20
After swapping the 1st number is : 20
After swapping the 2nd number is : 25

Flowchart:

C++ Code Editor:

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