# 2014. Longest Subsequence Repeated k Times

## Description

You are given a string `s`

of length `n`

, and an integer `k`

. You are tasked to find the **longest subsequence repeated** `k`

times in string `s`

.

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 **repeated** `k`

times in the string `s`

if `seq * k`

is a subsequence of `s`

, where `seq * k`

represents a string constructed by concatenating `seq`

`k`

times.

- For example,
`"bba"`

is repeated`2`

times in the string`"bababcba"`

, because the string`"bbabba"`

, constructed by concatenating`"bba"`

`2`

times, is a subsequence of the string`"`

.a__b__c__bab__"__ba__

Return *the longest subsequence repeated *

`k`

*times in string*

`s`

*. 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 = 2Output:"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 = 2Output:"b"Explanation:The longest subsequence repeated 2 times is "b".

**Example 3:**

Input:s = "ab", k = 2Output:""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.