Append Minimum Characters At End To Make Palindrome
Given a string s, find the minimum number of characters that must be appended to the end of s so that the final string becomes a palindrome.
You only need to return the minimum count of appended characters, not the final palindrome string.
Class
PalindromeAppender
Method
Minimum Characters To Append
int minimumCharactersToAppend(String s)
- Returns the minimum number of characters that must be appended at the end of
s.
- The appended characters can be chosen freely from lowercase English letters.
- The final string must read the same from left to right and right to left.
- If
s is already a palindrome, return 0.
Constraints
1 ≤ s.length() ≤ 100,000s contains only lowercase English letters.
Examples
Example 1
minimumCharactersToAppend(s = "race")
Output: 3
Explanation: Append "car" to get "racecar", which is a palindrome.
Example 2
minimumCharactersToAppend(s = "abab")
Output: 1
Explanation: Append "a" to get "ababa", which is a palindrome.
Example 3
minimumCharactersToAppend(s = "madam")
Output: 0
Explanation: The string is already a palindrome, so no character needs to be appended.
Example 4
minimumCharactersToAppend(s = "abcdc")
Output: 2
Explanation: Append "ba" to get "abcdcba", which is a palindrome.