K Palindrome
https://app.codesignal.com/interview-practice/task/x3rJpdZGEcjmYtDqv/description
---
A string is a k-palindrome if it can be transformed into a palindrome by removing any amount of characters from 0 to k. Your task is to determine whether the given string s is a k-palindrome.
Example
For
s = "abrarbra"andk = 1, the output should bekpalindrome(s, k) = true.You can remove one letter,
'r', to obtain the string"abrarba", which is a palindrome.For
s = "adbcdbacdb"andk = 2, the output should bekpalindrome(s, k) = false.
Input/Output
[execution time limit] 3 seconds (java)
[input] string s
A string containing only lowercase English letters.
Guaranteed constraints:
3 ≤ s.length ≤ 100.[input] integer k
Guaranteed constraints:
1 ≤ k ≤ 20.[output] boolean
- Return
trueif it is possible to delete at mostkletters from a stringsin order to make it palindrome. Returnfalseotherwise.
- Return
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| boolean kpalindrome(String s, int k) { | |
| Boolean[][] memo = new Boolean[s.length()][s.length()]; | |
| return dfs(s, k, 0, s.length() - 1, memo); | |
| } | |
| boolean dfs(String s, int k, int lo, int hi, Boolean[][] memo) { | |
| if (lo >= hi) { | |
| return true; | |
| } | |
| if (memo[lo][hi] != null) { | |
| return memo[lo][hi]; | |
| } | |
| while (lo < hi) { | |
| if (s.charAt(lo) != s.charAt(hi)) { | |
| break; | |
| } | |
| lo++; | |
| hi--; | |
| } | |
| boolean ans = k >= 0 && (dfs(s, k - 1, lo + 1, hi, memo) || dfs(s, k - 1, lo, hi - 1, memo)); | |
| memo[lo][hi] = ans; | |
| return ans; | |
| } |
