C# Palindrome Stack not working

Question

i would like your help with my program. I'm trying to check if the user input is a palindrome. This is my code.

        Stack cstack = new Stack();
        Stack rstack = new Stack();
        Console.WriteLine("Enter a palindrome string");
        string input = Console.ReadLine();

        foreach (char c in input)
        {
            cstack.Push(c);
        }

        foreach (var v in cstack)
        {
            rstack.Push(v);
        }

        if (cstack.Equals(rstack))
        {
            Console.Write("String is a palindrome");
        }
        else
        {
            Console.Write("String is not a palindrome");
        }

        Console.ReadLine();

So what i hope my code is doing is getting input from the user. Pushing the user input as characters into the cstack using a foreach loop. Reversing the characters in the cstack (Which should hold the users input) into a new stack called rstack using another foreach loop. Then using an if else statement which will check to see if the c stack which holds the original input is equal to the reverse stack. This comparison will determine if the string is a palindrome.

Cheers everyone for the help. I'm glad i didn't come out as an idiot with no clue as to what he was doing.

Sorry guys but would anyone know how to make it so the palindrome ignores case sensitivity. I assume you convert the string into lowercase with the ToLower, but really i have no idea I've never needed a string to be case insensitive before.

Is it mandatory to use Stack to solve this issue? You can solve this without using Stack.. — Chetan, Mar 24 '18 at 06:37
If you really want to use 2 stacks, you can replace `(cstack.Equals(rstack))` with `(cstack.SequenceEquals(rstack))` — vc 74, Mar 24 '18 at 07:01
Cheers for the advice. From what your implying it seems i wasn't as code efficient as i could be. — nat1, Mar 24 '18 at 07:10
@nat1 : did below answer address what you been looking for ? — rahulaga-msft, Mar 24 '18 at 07:16

rahulaga-msft · Accepted Answer · 2018-03-25T06:04:39.640

1

Stack<char> cstack = new Stack<char>();
            string input = "PoP";

            var inputToUpper = input.ToUpper(); /*assuming case senstivity is not to be considered */

            foreach (char c in inputToUpper)
            {
                cstack.Push(c);
            }

            bool isPalindrome = true;
            var noOfItems = cstack.Count;

            for(int i=0; i< noOfItems ; i++)
            {
                if (inputToUpper[i] != cstack.Pop())
                {
                    isPalindrome = false; break;
                }
            }

            if (isPalindrome)
            {
                Console.WriteLine("Palindrome");
            }
            else
            {
                Console.WriteLine("Non Palindrome");
            }

You can refer live demo here

edited Mar 25 '18 at 06:04

answered Mar 24 '18 at 06:37

rahulaga-msft

3,964
6
26
44

Thank you for the help. I'm sorry my requirement forced you to edit your code. – nat1 Mar 24 '18 at 06:48
A more efficient solution would be to use a for loop, and then compare the character at each part of the string to the popped value. Then you can exit early if it isn't a palindrome. – ProgrammingLlama Mar 24 '18 at 07:20

score 0 · Answer 2 · answered Oct 23 '19 at 11:04

This palindrome solution works for palindrome sentences with spaces

private static bool isPalinDrome(string word)
    {
        word = word.ToLower();
        word = word.Replace(" ", "");
        char[] wordArray = word.ToCharArray();
        String reverseWord = "";

        for (int i = wordArray.Length - 1; i >= 0; i--)
        {
            reverseWord = reverseWord + wordArray[i];
        }

        if (word == reverseWord)
        {
            return true;
        }

        return false;
    }

C# Palindrome Stack not working

2 Answers2