#2030

Smallest K-Length Subsequence With Occurrences of a Letter

master · 1710 · lc hard +32 · verified · 39.7% accepted · 512 likes · top 19%

Description

Given a string s, integers k and repetition, and a character letter, find the lexicographically smallest subsequence of s that has length exactly k and contains letter at least repetition times. It is guaranteed that letter appears at least repetition times in s.

Example 1:

Input: s = "leet", k = 3, letter = "e", repetition = 1

Output: "eet"

Explanation: There are four subsequences of length 3 that have the letter 'e' appear at least 1 time:

- "lee" (from "leet")

- "let" (from "leet")

- "eet" (from "leet")

The lexicographically smallest subsequence among them is "eet".

Example 2:

Input: s = "leetcode", k = 4, letter = "e", repetition = 2

Output: "ecde"

Explanation: "ecde" is the lexicographically smallest subsequence of length 4 that has the letter "e" appear at least 2 times.

Example 3:

Input: s = "bb", k = 2, letter = "b", repetition = 2

Output: "bb"

Explanation: "bb" is the only subsequence of length 2 that has the letter "b" appear at least 2 times.

Code

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class Solution:
    def smallestSubsequence(self, s: str, k: int, letter: str, repetition: int) -> str:

class Solution:
    def smallestSubsequence(self, s: str, k: int, letter: str, repetition: int) -> str: