Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns in C++

Solution: Next Palindrome Using Same Digits

Explore an efficient method to find the next smallest palindrome larger than a given numeric palindrome by rearranging its digits. Learn to use the two pointers technique to manipulate the left half of the string and mirror it, optimizing the process to handle both even and odd length palindromes. Understand how to find next lexicographical permutations and apply swaps and reversals to achieve the desired palindrome efficiently.

We'll cover the following...

Statement

Given a numeric string, numStr, representing a palindromeA palindrome is a number that reads the same backward as it does forward. (composed only of digits). Return the smallest palindrome larger than numStr that can be created by rearranging its digits. If no such palindrome exists, return an empty string "".

Consider the following example to understand the expected output for a given numeric string:

  • input string = "123321"

  • The valid palindromes made from the exact digits are "213312", "231132", "312213", "132231", "321123".

  • We return the palindrome "132231" because it is the smallest palindrome larger than the input string "123321".

Constraints:

  • ...