How hard is LeetCode 1451. Rearrange Words in a Sentence?

LeetCode 1451. Rearrange Words in a Sentence is rated Medium on LeetCode.

What topics does LeetCode 1451. Rearrange Words in a Sentence cover?

LeetCode 1451. Rearrange Words in a Sentence is tagged String and Sorting on LeetCode.

MediumNo. 1451

Rearrange Words in a Sentence — LeetCode 1451 Python Solution

Pattern: Sorting
Topics: String, Sorting
Reading time: 2 min
Source: leetcode.com

The problem

Given a sentence text (A sentence is a string of space-separated words) in the following format: First letter is in upper case. Each word in text are separated by a single space.

Example

Input: text = "Leetcode is cool"
Output: "Is cool leetcode"
Explanation: There are 3 words, "Leetcode" of length 8, "is" of length 2 and "cool" of length 4.

Python solution

PythonSolution

class Solution:
    def arrangeWords(self, text: str) -> str:
        words = text.split()
        words[0] = words[0].lower()
        words.sort(key=len)
        words[0] = words[0].title()
        return " ".join(words)

Complexity

Time: O(n log n)
Space · auxiliary: O(1) to O(n)

Pattern: Sorting

Spend O(n log n) once to buy an ordering that makes the rest of the problem trivial. LeetCode 1451. Rearrange Words in a Sentence is filed here because LeetCode tags it Sorting, which is the vocabulary this hub collects.

The sorting guide has the Python template for the pattern and the 401 LeetCode problems that use it.

Related problems
No.	Problem	Difficulty
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0937	Reorder Data in Log Files	Medium
1859	Sorting the Sentence	Easy
2785	Sort Vowels in a String	Medium
0056	Merge Intervals	Medium

Frequently asked questions

How hard is LeetCode 1451. Rearrange Words in a Sentence?: LeetCode 1451. Rearrange Words in a Sentence is rated Medium on LeetCode.
What topics does LeetCode 1451. Rearrange Words in a Sentence cover?: LeetCode 1451. Rearrange Words in a Sentence is tagged String and Sorting on LeetCode.

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python

Please analyze this context and help me answer the question or solve the problem.

Transcript

"Okay, next one. Given a string, return the length of the longest substring that has no repeating characters. Walk me through your approach before you code it."

Technical interview · 45 minsolution.pyShared editor · Python 3Longest substring without repeatsMediumGiven a string s, return the length of the longest contiguous substring in which every character is unique.s = "abcabcbb"
→ 31def length_of_longest_substring(s: str) -> int:2 last_seen = {}3 left = best = 04 for right, ch in enumerate(s):5 if ch in last_seen and last_seen[ch] >= left:

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 Terra

Transcribing...

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

Transcript

"Okay, next one. Given a string, return the length of the longest substring that has no repeating characters. Walk me through your approach before you code it."

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 TerraClear chat

Transcribing...

QuitEscHide+QCapture+PCrop+OSubmit+EnterPress to get answerLeft/Right+Up/Down+

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

Transcript

"Okay, next one. Given a string, return the length of the longest substring that has no repeating characters. Walk me through your approach before you code it."

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 TerraClear chat

Transcribing...

Primary display

QuitEscHide+QCapture+PCrop+OSubmit+EnterPress to get answerLeft/Right+Up/Down+

The problem

Example

Python solution

Complexity

Pattern: Sorting

Related problems

Frequently asked questions

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Approach

Approach

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