TCS Coding Practice Question | Swap two Numbers

Given two numbers, the task is to swap the two numbers using Command Line Arguments. Examples:

Input: n1 = 10, n2 = 20
Output: 20 10

Input: n1 = 100, n2 = 101
Output: 101 100

Approach:

Since the numbers are entered as Command line Arguments, there is no need for a dedicated input line
Extract the input numbers from the command line argument
This extracted numbers will be in string type.
Convert these numbers into integer type and store it in variables, say num1 and num2
Get the sum in one of the two given numbers.
The numbers can then be swapped using the sum and subtraction from the sum.

Program:

// C program to swap the two numbers
// using command line arguments

#include <stdio.h>
#include <stdlib.h> /* atoi */

// Function to swap the two numbers
void swap(int x, int y)
{
    // Code to swap ‘x’ and ‘y’

    // x now becomes x+y
    x = x + y;

    // y becomes x
    y = x - y;

    // x becomes y
    x = x - y;

    printf("%d %d\n", x, y);
}

// Driver code
int main(int argc, char* argv[])
{

    int num1, num2;

    // Check if the length of args array is 1
    if (argc == 1)
        printf("No command line arguments found.\n");

    else {

        // Get the command line argument and
        // Convert it from string type to integer type
        // using function "atoi( argument)"
        num1 = atoi(argv[1]);
        num2 = atoi(argv[2]);

        // Swap the numbers and print it
        swap(num1, num2);
    }
    return 0;
}

Java

// Java program to swap the two numbers
// using command line arguments

class GFG {

    // Function to swap the two numbers
    static void swap(int x, int y)
    {
        // Code to swap ‘x’ and ‘y’

        // x now becomes x+y
        x = x + y;

        // y becomes x
        y = x - y;

        // x becomes y
        x = x - y;

        System.out.println(x + " " + y);
    }

    // Driver code
    public static void main(String[] args)
    {

        // Check if length of args array is
        // greater than 0
        if (args.length > 0) {

            // Get the command line argument and
            // Convert it from string type to integer type
            int num1 = Integer.parseInt(args[0]);
            int num2 = Integer.parseInt(args[1]);

            // Swap the numbers
            swap(num1, num2);
        }
        else
            System.out.println("No command line "
                               + "arguments found.");
    }
}

Output:

In C:
In Java:

Time Complexity: O(1)
Auxiliary Space: O(1)

TCS Coding Practice Question | Swap two Numbers

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