Algorithms: Check if a String Is a Palindrome in 4 Different Ways (2024)

FAQs

What is the most efficient way to check a palindrome? ›

One approach to checking if a number is a palindrome is to reverse the digits of the number and compare it with the original number. If the reversed number is the same as the original number, then the number is a palindrome.

Count occurrences of all characters. Count odd occurrences. If this count is greater than 1 or is equal to 1 and length of the string is even then obviously palindrome cannot be formed from the given string.

Just set a variable,end, to the last char in string one and another to the first, begin, in string two, compare the begin char to the end of the second string. subtract 1 from the end pointer and add one to the begin pointer. if they are equal or end is less than begin, we are done and it's a palindrome.

An algorithm for palindromes

If you want to check if a word, phrase, or number is a palindrome. we can use the following pseudocode to check for a palindrome: Firstly, reverse the word, phrase, or number. Then, check if reversed string or phrase is equal to the original or not.

Manacher's Algorithm has one single application. It is used to find the Longest Palindromic Sub-string in any string. This algorithm is required to solve sub-problems of some very hard problems. This article explains the basic brute force method first and then moves on to explain the optimized Manacher's Algorithm.

Manacher's algorithm is a string-matching algorithm that is used to find the longest palindromic substring in a given string. It was developed by Michael O. Rabin and Richard M. Karp in 1975 and later improved by G.

Alternative Method:

The algorithm for the source code for this palindrome Python program is that it checks the characters of the string from half the length. def check_palin (str): for i in range (0, int (len (str)/2)): if str [i] !=

The first 30 palindromic numbers (in decimal) are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, ... (sequence A002113 in the OEIS). Palindromic numbers receive most attention in the realm of recreational mathematics.

Since the last letter must be the same as the first letter, and the third letter must be the same as the second letter, we can form 26*26*1*1 = 676 such 4-letter palindromes. You can manually create the list alphabetically like this: aaaa. abba.

The term derives from the Greek palin dromo (“running back again”). Examples of word palindromes include “civic,” “madam,” “radar,” and “deified.” Numerical palindromes include sequences that read the same in reverse order (e.g., 1991), as well as those that can be read upside down and backward (e.g., 1961).

How do you write an algorithm to check if a number is a palindrome or not in Python? ›

String Palindrome Program in Python

n=int(input("Enter number:")) temp=n rev=0 while(n>0): dig=n%10 rev=rev*10+dig n=n//10 if(temp==rev): print("The number is a palindrome!") else: print("The number isn't a palindrome!")

number=int(input("Enter any number :")) #store a copy of this number temp=number #calculate reverse of this number reverse_num=0 while(number>0): #extract last digit of this number digit=number%10 #append this digit in reveresed number reverse_num=reverse_num*10+digit #floor divide the number leave out the last digit ...