How hard is LeetCode 631. Design Excel Sum Formula?

LeetCode 631. Design Excel Sum Formula is rated Hard on LeetCode.

What is the time complexity of LeetCode 631. Design Excel Sum Formula?

The Python solution on this page runs in O(n).

What is the space complexity of LeetCode 631. Design Excel Sum Formula?

The Python solution on this page uses O(n) auxiliary space.

What topics does LeetCode 631. Design Excel Sum Formula cover?

LeetCode 631. Design Excel Sum Formula is tagged Graph, Design, Topological Sort, Array, Hash Table, String and Matrix on LeetCode.

Is LeetCode 631. Design Excel Sum Formula a premium problem?

Yes. LeetCode 631. Design Excel Sum Formula is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.

HardNo. 0631LeetCode Premium

Design Excel Sum Formula — LeetCode 631 Python Solution

Pattern: Topological Sort
Topics: Graph, Design, Topological Sort, Array, Hash Table, String, Matrix
Reading time: 2 min
Source: leetcode.com

The problem

Design the basic function of Excel and implement the function of the sum formula. Implement the Excel class: Excel(int height, char width) Initializes the object with the height and the width of the sheet.

Example

Input: ["Excel", "set", "sum", "set", "get"]
Output: [null, null, 4, null, 6]
Explanation: Excel excel = new Excel(3, "C");

Complexity

Time: O(n)
Space · auxiliary: O(n)

Pattern: Topological Sort

Order a set of tasks so that every dependency comes before the thing that needs it. LeetCode 631. Design Excel Sum Formula is filed here because LeetCode tags it Topological Sort, which is the vocabulary this hub collects.

The topological sort guide has the Python template for the pattern and the 32 LeetCode problems that use it.

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Frequently asked questions

How hard is LeetCode 631. Design Excel Sum Formula?: LeetCode 631. Design Excel Sum Formula is rated Hard on LeetCode.
What is the time complexity of LeetCode 631. Design Excel Sum Formula?: The Python solution on this page runs in O(n).
What is the space complexity of LeetCode 631. Design Excel Sum Formula?: The Python solution on this page uses O(n) auxiliary space.
What topics does LeetCode 631. Design Excel Sum Formula cover?: LeetCode 631. Design Excel Sum Formula is tagged Graph, Design, Topological Sort, Array, Hash Table, String and Matrix on LeetCode.
Is LeetCode 631. Design Excel Sum Formula a premium problem?: Yes. LeetCode 631. Design Excel Sum Formula is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.

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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

Complexity

Pattern: Topological Sort

Related problems

Frequently asked questions

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Approach

Approach

Approach