## Q. Write an algorithm and program to swap two numbers without using temporary variable.

Solution : We can swap two numbers without using temporary variable. By using + and - operator we can swap two number.

Swapping two number :- Swap two numbers means exchange the values of two variables with each other.
For example:
Before Swapping : num1 = 10 and num2 = 20.
After Swapping : num1 = 20 and num2 = 10.

#### Swap two numbers without using third variable algorithm

```//Algorithm To Swap Two Numbers Without Temporary Variable
START
Step 1 ->  Take two integer as input num1 and num2.
Step 2 ->  Print number before swapping
Step 3 ->  num1 = num1 + num2;
Step 4 ->  num2 = num1 - num2;
Step 5 ->  num1 = num1 - num2;
Step 6 ->  Print numbers after swapping
STOP
```

#### Swap Two Numbers Without Using Temporary Variable Program

• C
• C++
• Java
• Python
• C#
• PHP
• ```//C Program To Swap Two Numbers Without Temporary Variable.
#include <stdio.h>
int main()
{
int num1,num2;
printf("Enter Two Numbers :\n");
scanf("%d %d",&num1,&num2);
printf("Number before swapping is %d and %d \n",num1,num2);
num1=num1+num2;
num2=num1-num2;
num1=num1-num2;
printf("Number after swapping is %d and %d \n",num1,num2);
return 0;
}
```
```//C++ Program To Swap Two Numbers Without Temporary Variable.
#include <iostream>
using namespace std;
int main()
{
int num1,num2;
cout<<"Enter Two Numbers :\n";
cin>>num1>>num2;
cout<<"Number before swapping is "<<num1<<" and "<<num2<<"\n";
num1=num1+num2;
num2=num1-num2;
num1=num1-num2;
cout<<"Number after swapping is "<<num1<<" and "<<num2;
return 0;
}
```
```//Java Program To Swap Two Numbers Without Temporary Variable.
import java.util.Scanner;
public class LFC
{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.print("Enter Two Numbers :");
int num1 = scan.nextInt();
int num2 = scan.nextInt();
System.out.println("Number before swapping is "+num1+" and "+num2);
num1=num1+num2;
num2=num1-num2;
num1=num1-num2;
System.out.println("Number after swapping is "+num1+" and "+num2);
}
}
```
```//Python Program To Swap Two Numbers Without Temporary Variable.
print('Enter Two Numbers :')
num1 = int(input())
num2 = int(input())
print("Number before swapping is ",num1," and ",num2)
num1 = num1 + num2;
num2 = num1 - num2;
num1 = num1 - num2;
print("Number after swapping is ",num1," and ",num2)
```
```//C# Program To Swap Two Numbers Without Temporary Variable.
using System;
class LFC {
static void Main() {
int num1=10,num2=15;
Console.WriteLine("Number before swapping is "+num1+" and "+num2);
num1=num1+num2;
num2=num1-num2;
num1=num1-num2;
Console.WriteLine("Number After swapping is "+num1+" and "+num2);
}
} ```
```//PHP Program To Swap Two Numbers Without Temporary Variable.
<?php
\$num1=10;
\$num2=20;
echo "Number before swapping is \$num1 and \$num2 \n";
\$num1=\$num1+\$num2;
\$num2=\$num1-\$num2;
\$num1=\$num1-\$num2;
echo "Number after swapping is \$num1 and \$num2";
?>```
```//C Program To Swap Two Numbers Without Temporary Variable.
#include <stdio.h>
int main()
{
int num1,num2;
printf("Enter two numers : \n");
scanf("%d %d",&num1,&num2);
printf("Number before swapping is %d and %d \n",num1,num2);
num1=num1+num2;
num2=num1-num2;
num1=num1-num2;
printf("Number after swapping is %d and %d \n",num1,num2);
return 0;
}
```

#### Output

```Enter Two Numbers :
10 15
Number before swapping is 10 and 15
Number after swapping is 15 and 10
```

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