TCS Coding Practice Question | Palindrome String

Given a string, the task is to check if this String is Palindrome or not using Command Line Arguments.

Examples:

Input: str = "Geeks"
Output: No

Input: str = "GFG"
Output: Yes

Approach:

• Since the string is entered as Command line Argument, there is no need for a dedicated input line
• Extract the input string from the command line argument
• Traverse through this String character by character using loop, till half the length of the sting
• Check if the characters from one end match with the characters from the other end
• If any character do not matches, the String is not Palindrome
• If all character matches, the String is a Palindrome

Program:

C

// C program to check if a string is Palindrome
// using command line arguments

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Function to reverse a string
int isPalindrome(char* str)
{
    int n = strlen(str);
    int i;

    // Check if the characters from one end
    // match with the characters
    // from the other end
    for (i = 0; i < n / 2; i++)
        if (str[i] != str[n - i - 1])

            // Since characters do not match
            // return 0 which resembles false
            return 0;

    // Since all characters match
    // return 1 which resembles true
    return 1;
}

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

    int res = 0;

    // 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 check if it is Palindrome
        res = isPalindrome(argv[1]);

        // Check if res is 0 or 1
        if (res == 0)
            // Print No
            printf("No\n");
        else
            // Print Yes
            printf("Yes\n");
    }
    return 0;
}

Java

// Java program to check if a string is Palindrome
// using command line arguments

class GFG {

    // Function to reverse a string
    public static int isPalindrome(String str)
    {
        int n = str.length();

        // Check if the characters from one end
        // match with the characters
        // from the other end
        for (int i = 0; i < n / 2; i++)
            if (str.charAt(i) != str.charAt(n - i - 1))

                // Since characters do not match
                // return 0 which resembles false
                return 0;

        // Since all characters match
        // return 1 which resembles true
        return 1;
    }

    // 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 check if it is Palindrome
            int res = isPalindrome(args[0]);

            // Check if res is 0 or 1
            if (res == 0)
                // Print No
                System.out.println("No\n");
            else
                // Print Yes
                System.out.println("Yes\n");
        }
        else
            System.out.println("No command line "
                               + "arguments found.");
    }
}

Output:

• In C:
• In Java: