leecode1816.md

1816. 截断句子

地址:https://leetcode-cn.com/problems/truncate-sentence/

题目描述

句子 是一个单词列表，列表中的单词之间用单个空格隔开，且不存在前导或尾随空格。每个单词仅由大小写英文字母组成（不含标点符号）。

例如，"Hello World"、"HELLO" 和 "hello world hello world" 都是句子。 给你一个句子 s 和一个整数 k ，请你将 s 截断，使截断后的句子仅含 前 k 个单词。返回 截断 s 后得到的句子。

示例1

输入：s = "Hello how are you Contestant", k = 4
输出："Hello how are you"
解释：
s 中的单词为 ["Hello", "how" "are", "you", "Contestant"]
前 4 个单词为 ["Hello", "how", "are", "you"]
因此，应当返回 "Hello how are you"

示例2

输入：s = "What is the solution to this problem", k = 4
输出："What is the solution"
解释：
s 中的单词为 ["What", "is" "the", "solution", "to", "this", "problem"]
前 4 个单词为 ["What", "is", "the", "solution"]
因此，应当返回 "What is the solution"

示例3

输入：s = "chopper is not a tanuki", k = 5
输出："chopper is not a tanuki"

我的解法

class Solution:
    def truncateSentence(self, s: str, k: int) -> str:
        return  " ".join(s.split(' ')[:k])

参考解法

class Solution:
    def truncateSentence(self, s: str, k: int) -> str:
        n, end, count = len(s), 0, 0
        for i in range(1, n + 1):
            if i == n or s[i] == ' ':
                count += 1
                if count == k:
                    end = i
                    break
        return s[:end]