Questions tagged [palindrome]
Any sequence of units (typically letters or numbers) that are read the same way forward or backward.
228
questions
4
votes
1answer
44 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 ...
9
votes
5answers
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 ...
7
votes
2answers
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
0answers
47 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
0answers
80 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 ...
0
votes
3answers
67 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 ...
6
votes
3answers
511 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 ...
3
votes
1answer
79 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
3answers
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
2answers
277 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
1answer
307 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 (...
1
vote
2answers
66 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] ...
3
votes
0answers
189 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
4answers
176 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.
...
0
votes
0answers
80 views
Split string into as few substrings as possible such that each substring is a palindrome
The task
Given a string, split it into as few strings as possible such that
each string is a palindrome.
For example, given the input string racecarannakayak, return
["racecar", "anna", "...
0
votes
1answer
63 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.
...
6
votes
3answers
1k 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:
...
4
votes
1answer
117 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 '...
11
votes
5answers
847 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
2answers
407 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
1answer
76 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
4answers
206 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
1answer
158 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
2answers
207 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 ...
2
votes
0answers
181 views
Longest Palindromic Substring challenge
My code is a mix-up between dynamic programming with the HashMap and brute force with the way I reach out the results and substring. I don't know how to optimize my ...
4
votes
2answers
77 views
Solve Project Euler #4 in PHP
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 product of two 3-digit ...
3
votes
4answers
3k views
Find longest Palindrome substring
I am preparing for technical interview and I found this question on geeksforgeeks, but I did not understand their solution. So, I have written my own solution. I want to optimize this code.
...
-2
votes
1answer
82 views
Find the first palindrome larger than the given number
Question
Input number of test cases.
Input each test case and output its next palindrome number.
Link: https://www.spoj.com/problems/PALIN/
Language Used: C++14 (gcc 6.3)
My code
...
1
vote
1answer
47 views
A program that checks for Palindromness
Yes, I made it up.
This program checks if an entered string is a palindrome or not by assigning a char variable the characters ...
2
votes
2answers
132 views
Find a palindromic string in C
This program tests whether a string is a palindrome or not.
Can there be any improvements or shortcuts that can be used in the program. You can give any type of string as input. The program finds does ...
10
votes
5answers
441 views
7
votes
3answers
1k views
The Next Palindromic number
I have incremented an integer in the function nextpalin() and converted it into a std::string for finding whether it's a ...
0
votes
1answer
146 views
Find largest palindrome from the product of two 3-digit numbers
I think this is a good solution to finding the largest numeric palindrome that can be formed from the product of two 3-digit numbers... But it seems like there are some improvements that we could make ...
7
votes
1answer
2k views
Check if a given linked list is palindrome
I am solving interview questions from here.
Problem :Given a singly linked list, determine if its a palindrome. Return 1 or 0 denoting if its a palindrome or not, respectively.
Notes:Expected ...
4
votes
2answers
1k views
Next palindromic number
I wrote a function that takes a number and finds the next palindromic number. Time complexity is currently O(n2), which is really bad. How could one make this function more efficient?
...
15
votes
5answers
5k views
Palindrome checking function
I recently did a little task for fun that required me to create a class to determine if a word is a palindrome or not. I know this is quite simple, but I'd be interested to know if a real developer (I'...
0
votes
1answer
50 views
Finding time complexity of my solution to the 'longest palindrome' problem in Python
Here is a short version!
...
1
vote
2answers
5k views
Count palindrome substrings
Given a string S, count and return the number of substrings of S that
are palindromes. Single length substrings are also palindromes. We
just have to count the substring that are palindrome.
...
0
votes
2answers
2k views
Palindrome algorithm
This code could be better?
This is the algorithm:
Compare the 1st character to the last character
Compare the 2nd character to the second last character and so on
Stop when the middle of the ...
3
votes
2answers
3k views
Largest palindrome made from the product of 3-digit numbers
I am given a task to write a program to find the largest palindrome made from the product of two 3-digit numbers. How can I improve this code?
...
4
votes
2answers
827 views
Finding palindromic strings of even length
Given a string of digits. Find the length of longest substring of even length i.e. 0,2,... which is a palindrome or which can be rearranged to form a palindrome (see example below).
Here is my code: ...
6
votes
2answers
2k views
Counting the number of continuous palindromic substrings
Given a string of lowercase ASCII characters, find all distinct continuous palindromic sub-strings of it.
Here is my code:
...
4
votes
1answer
752 views
C++ check if Palindrome
Just did this simple application to check whether a string is a palindrome or not
...
1
vote
0answers
487 views
Python palindrome function; is it possible to write it without using string conversion?
I hope this question is okay to ask on Code Review; this is a little function I wrote in Python 2.7.12 that checks if a number is a palindrome. It works fine but I'd like to know if there is a purely ...
2
votes
1answer
67 views
Performing the Lychrel algorithm in Rust
A Lychrel number is a natural number that cannot form a palindrome through the iterative process of repeatedly reversing its digits and adding the resulting numbers.
In the code below I'm trying to ...
3
votes
2answers
1k views
Find a substring which could be rearranged into a palindrome
Problem statement:
To find maximum length substring in an input string which could be
arranged into a palindrome, only even length palindromes are expected.
Input is one line String which ...
12
votes
10answers
6k views
Tests for palindromes in C and C++
A question I've been asked on interactive phone screens is to code a test to determine whether a string is
a palindrome or not. I am providing two examples here: one in C and one in C++. They both ...
1
vote
0answers
107 views
C# Project Euler #4: Program that finds Largest palindrome product
So I made a code to improve my programming skills and it works just fine, but it looks chaotic for me. Is there is a better and more efficient way to do it? If you have any ideas/tips I would love to ...
7
votes
4answers
5k views
Find palindromic substrings as efficiently as possible
I've written a function to calculate all the distinct substrings of a given string, that are palindromes. The string is passed as the argument to the function. For example, the string abba is a ...
3
votes
1answer
870 views
Valid Alphanumeric Palindrome
Valid Alphanumeric Palindrome
Problem (from Leetcode)
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example, ...
