Class Solution
- java.lang.Object
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- g2001_2100.s2014_longest_subsequence_repeated_k_times.Solution
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public class Solution extends Object
2014 - Longest Subsequence Repeated k Times.Hard
You are given a string
s
of lengthn
, and an integerk
. You are tasked to find the longest subsequence repeatedk
times in strings
.A subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.
A subsequence
seq
is repeatedk
times in the strings
ifseq * k
is a subsequence ofs
, whereseq * k
represents a string constructed by concatenatingseq
k
times.- For example,
"bba"
is repeated2
times in the string"bababcba"
, because the string"bbabba"
, constructed by concatenating"bba"
2
times, is a subsequence of the string"**b**a**bab**c**ba**"
.
Return the longest subsequence repeated
k
times in strings
. If multiple such subsequences are found, return the lexicographically largest one. If there is no such subsequence, return an empty string.Example 1:
Input: s = “letsleetcode”, k = 2
Output: “let”
Explanation: There are two longest subsequences repeated 2 times: “let” and “ete”. “let” is the lexicographically largest one.
Example 2:
Input: s = “bb”, k = 2
Output: “b”
Explanation: The longest subsequence repeated 2 times is “b”.
Example 3:
Input: s = “ab”, k = 2
Output: ""
Explanation: There is no subsequence repeated 2 times. Empty string is returned.
Constraints:
n == s.length
2 <= n, k <= 2000
2 <= n < k * 8
s
consists of lowercase English letters.
- For example,
-
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Constructor Summary
Constructors Constructor Description Solution()
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