Questions tagged [palindrome]

Any sequence of units (typically letters or numbers) that are read the same way forward or backward.

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Find long palindrome multiplications in modern C++

I'm a former C# programmer, updating my rusty C++98 (perhaps I should try Rust instead) to modern C++20. My main goal is to get used to C++ standard library types and algorithms. I chose to solve a ...
3 votes
1 answer
150 views

Longest Palindromic Substring | Python Code Giving TLE

Problem Statement Given a string s , return the longest palindromic substring in s. Constraints ...
3 votes
3 answers
224 views

The largest palindrome made from the product of two 3-digit numbers

Problem description: A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99. Find the largest palindrome made from the ...
1 vote
1 answer
57 views

isPalindrom-function in TypeScript

I have written an isPalindrom-Function in TypeScript. ...
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0 votes
1 answer
35 views

Is my approach for Palindrome right or is there a better way to do it?

The code below is for checking whether the input string is palindrome or not ...
1 vote
1 answer
153 views

Find next biggest palindrome

I have written a program for the SPOJ PALIN problem: A positive integer is called a palindrome if its[decimal representation is the same]from left to right and from right to left. For a given ...
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1 vote
1 answer
73 views

Manacher Algorithm in Haskell

Please review the manacher algorithm in haskell. Find the longest Palindrome in a String. ...
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2 votes
1 answer
134 views

Finding the next palindrome number

I wrote a piece of code that generates the next palindromic number and that works fine. However I feel like my code isn't as efficient as it could be. Are there any tweaks that I could implement to ...
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0 votes
0 answers
74 views

Calculate the largest palindrome under x-digits multiplication

Here is my Rust program: ...
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7 votes
5 answers
935 views

Checking whether a string is a permutation of a palindrome in C++20 - follow-up

This post is the follow-up of Checking whether a string is a permutation of a palindrome in C++20. So, what's new? Well, nothing else except that the procedure is now generic and accepts all ...
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10 votes
4 answers
1k views

Checking whether a string is a permutation of a palindrome in C++20

(See the next iteration/follow-up here.) I have this short function is_permutation_palindrome, which returns true only if the ...
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5 votes
7 answers
2k views

Determine if a word is a palindrome

I'm a newbie programmer and was given a task to find if the input word is a palindrome or not. Now, I've written the program to the best of my ability but would like to know how it could be improved. ...
1 vote
1 answer
89 views

Finding longest palindromic substring in a string (gives TLE on leetcode)

I'm solving the Longest Palindromic Substring problem on LeetCode. And here's my final submission: ...
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1 vote
1 answer
72 views

Optimizing Code for Project Euler Problem 04

I just finished Problem 04 on Project Euler, and I was looking at ways to optimize my code, just started learning functions too, so I'm pretty sure it's very bad, hopefully you guys can help me. ...
4 votes
2 answers
135 views

Longest Palindromic Subsequence Multithread in C

I'm trying to learn how to multithread with c, and thought that the longest palindromic subsequence problem would be a good place to start. The idea is that we run two threads and compare their ...
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2 votes
3 answers
378 views

Finding n-th smallest Palindrome number (where 1<=n<=5000 and the palindrome number must have odd number of digits)

I am working on this code from 3 days from a website called Codechef, the code compiles, executes and even give correct results but my code is taking 1.01 sec, but the time limit for question is 1sec,...
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1 vote
2 answers
148 views

Find largest palindromic substrings in a string

I have written some code to find the largest palindromic sub-strings in a string without repeating any character. Example input abappabaxhhh output ...
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-1 votes
1 answer
215 views

Recursive Palindrome in JavaScript

Would someone review this code, and confirm that it is indeed recursive? I'm learning computer science and going through different types of algorithms. Right now, I'm focusing on recursion want to ...
0 votes
1 answer
86 views

Algorithm For Longest Palindrome

I made an brute force algorithm to find the longest palindrome within the string. This palindrome is a substring of the input. Below is the code. ...
4 votes
1 answer
390 views

Check if string is palindrome LeetCode

LeetCode 125 requires receiving a string and checking if it is a valid palindrome. I have done this and am confident with an int and a single word, but this question requires the use a of a sentence ...
3 votes
1 answer
106 views

palindrome code in C times out in program challenge?

Hello I am making a code in C to find the value of the last sequence of palindromes of a specified size (d) and I need to optimize this code as it is for an ...
9 votes
1 answer
2k views

LeetCode on Longest Palindromic Substring in Python

This is a programming question from LeetCode: Given a string s, return the longest palindromic substring in s. Example 1: Input: s = "babad" Output: "bab" Note: "aba" is ...
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4 votes
4 answers
1k views

Check if a binary tree is symmetric in Python

I have solved the following Leetcode problem. Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmetric....
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3 votes
2 answers
387 views

Palindrome Algorithm and JUnit 5 Tests

I have a "Palindrome" class that has some functions for verifying if certain things are Palindromes. For the verification, I have 2 different algorithms, one being recursive and the other ...
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2 votes
4 answers
794 views

Python palindrome checker function

For practice purposes I implemented a function that checks for palindromes: ...
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3 votes
1 answer
440 views

Optimizing code solution for Palindrome Index-Hackerrank

I submitted my solution for palindrome Index coding challenge but I get "test cases terminated due to time out error". My code is working and so I don't know what else to do to optimize it. Please ...
3 votes
0 answers
542 views

HackerRank's Challenging Palindromes solution times out for certain tests

I am trying to solve the Challenging Palindromes problem from HackerRank. The code that I have got so far fails only for large inputs due to timeout, every other test it passes successfully. The ...
4 votes
1 answer
68 views

A fast generator of palindrome dates in chronological order

02/02/2020 is a palindrome day because reading the date left-to-right or right-to-left still refers to the same calendar date. And because it doesn't matter whether you use the DD/MM/YYYY format or ...
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9 votes
5 answers
3k views

Palindrome checker program

I've been studying Java for some days and I'm just now starting to make some simple programs, I'd like to know if there's any 'noob' mistakes or habits that I could avoid. In other words: how could ...
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7 votes
2 answers
1k views

Python palindrome program

I have written a palindrome program. And I was just wondering if it correct? I checked using the words racecar and madam, and it says they are palindromes. I have also tested nonpalindrome words and ...
1 vote
0 answers
107 views

How do I optimize memoization in order to find longest palindromic substring?

I want to find the longest palindromic substring using dynamic programming in Python3. The strings can be as large as this string. I have seen other questions on this problem that successfully solve ...
3 votes
0 answers
166 views

Longest palindrome code in C# takes time out on LeetCode

I like to request a review of the code below, which is my attempt at answering the question here on LeetCode site. The code passes 43 tests, but it times out on the next one. I copied and ran the test ...
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0 votes
3 answers
99 views

Basic Palindrome check comparing chars

I've seen variations of this assignment where you reverse a string to match it to the original to find out if it is a palindrome, but this version I made only iterates through half of the string ...
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6 votes
3 answers
876 views

CTCI Chapter 1 : Palindrome Permutation

Below is my code for the problem 1.4 in CTCI. I would like a review of my code and if my approach to the problem is correct. Problem Statement: Palindrome Permutation: Given a string, write a ...
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3 votes
1 answer
202 views

Project Euler - Problem No.4 - Largest palindrome product

according to the problem: A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99. Find the largest palindrome made ...
4 votes
3 answers
2k views

Palindrome test

This is some code that determines if a string of characters is a palindrome or not. My professor says that there is a performance issue with the program, but I can't quite put my finger on it. Can ...
3 votes
2 answers
559 views

Calculate the largest palindromic number from the product of two 6-digit numbers (100000 to 999999)

Are there any efficient ways to solve this problem, for example using bitwise operator? ...
3 votes
1 answer
351 views

Palindromic partitions solution

Task Find the smallest number of cuts required to break a string into a set of valid palindromes. For example: ababbbabbababa becomes a|babbbab|b|ababa (cuts = 3) partytrapb becomes partytrap|b (...
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1 vote
1 answer
170 views

Palindrome Pairs

The task is taken from leetcode Given a list of unique words, find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] ...
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3 votes
0 answers
224 views

Longest Palindrome Substring: Where is the dynamic programming? [closed]

In this LeetCode problem, Longest Palindromic Substring, it is listed under Dynamic Programming for Google interview preparation. My understanding of dynamic programming is roughly "recursion + ...
4 votes
4 answers
242 views

Largest Palindrome Product - Project Euler #4

This is my code for Project Euler Problem #4 The question: A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99. Find ...
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-1 votes
1 answer
67 views

Why does my function think that "uiouioiu"is a plaindrome? [closed]

I was reading Introduction to Computation and Programming using Python and there in an exercise, we had to write a function which would tell us if a given word is a palindrome or not, recursively. ...
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6 votes
3 answers
2k views

Determine whether an integer is a palindrome

The task Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward. Example 1: Input: 121 Output: true Example 2: ...
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4 votes
1 answer
188 views

Return whether a string is a palindrome if you can delete at most k elements

The task: Given a string which we can delete at most k, return whether you can make a palindrome. For example, given 'waterrfetawx' and a k of 2, you could delete f and x to get '...
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11 votes
5 answers
950 views

Easy to read palindrome checker

I made a palindrome checker that's supposed to be designed to be simple and easy to read. Please let me know what you think. I believe the time complexity is \$\mathcal{O}(n)\$ but I'm not too sure ...
4 votes
2 answers
488 views

Longest Palindromic Substring better approach

I have encountered to this question and applied a brute force algorithm off top of my head and couldn't find a better optimized solution. I was hoping I could get some insight to implement a better ...
1 vote
1 answer
128 views

Check if given integer is a palindrome

This code checks if the given integer is a palindrome. If it is, prints given integer is a palindrome else, not a palindrome: ...
1 vote
4 answers
295 views

Read a palindrome of unknown length

I have a task to write the function: int read_palindrome(); // input comes from stdin which will read one line from standard input and returns 1 if the line is a ...
2 votes
1 answer
254 views

Find palindromes in circular rotated string

I'm trying to tackle a programming challenge to determine how many palindromes exist in a given string that is being rotated character by character. My solution works, but it's too slow, and I'm ...
10 votes
2 answers
324 views

Determining if a string can be permuted to a palindrome

I am going through Elements of Programming Interview by Aziz, Lee and Prakash one of the questions is how to determine if a string can be permuted to a palindrome. For example ...
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