LeetCode 1859. Sorting the Sentence

Description

https://leetcode.com/problems/sorting-the-sentence/

sentence is a list of words that are separated by a single space with no leading or trailing spaces. Each word consists of lowercase and uppercase English letters.

A sentence can be shuffled by appending the 1-indexed word position to each word then rearranging the words in the sentence.

• For example, the sentence "This is a sentence" can be shuffled as "sentence4 a3 is2 This1" or "is2 sentence4 This1 a3".

Given a shuffled sentence s containing no more than 9 words, reconstruct and return the original sentence.

Example 1:

Input: s = "is2 sentence4 This1 a3"
Output: "This is a sentence"
Explanation: Sort the words in s to their original positions "This1 is2 a3 sentence4", then remove the numbers.

Example 2:

Input: s = "Myself2 Me1 I4 and3"
Output: "Me Myself and I"
Explanation: Sort the words in s to their original positions "Me1 Myself2 and3 I4", then remove the numbers.

Constraints:

• 2 <= s.length <= 200
• s consists of lowercase and uppercase English letters, spaces, and digits from 1 to 9.
• The number of words in s is between 1 and 9.
• The words in s are separated by a single space.
• s contains no leading or trailing spaces.

Explanation

Split to words and base on the last character of each word to rebuild a sentence.

Python Solution

class Solution:
def sortSentence(self, s: str) -> str:

words = s.split()

results = [None for i in range(len(words))]

for word in words:
i = int(word[-1])

results[i - 1] = word[:len(word) - 1]

return " ".join(results)

• Time Complexity: O(N).
• Space Complexity: O(N).