What is the time complexity of LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array?

The Python solution on this page runs in O(n \times \log_{10} M), where n and M are the length of the array \textit{nums} and the maximum value of the elements in the array, respectively.

What is the space complexity of LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array?

The Python solution on this page uses O(1) auxiliary space.

EasyNo. 2535

Difference Between Element Sum and Digit Sum of an Array — LeetCode 2535 Python Solution

Pattern: Math and Number Theory
Topics: Array, Math
Reading time: 2 min
Source: leetcode.com

The problem

You are given a positive integer array nums. The element sum is the sum of all the elements in nums.

Example

Input: nums = [1,15,6,3]
Output: 9
Explanation: The element sum of nums is 1 + 15 + 6 + 3 = 25.

Python solution

PythonSolution

class Solution:
    def differenceOfSum(self, nums: List[int]) -> int:
        x = y = 0
        for v in nums:
            x += v
            while v:
                y += v % 10
                v //= 10
        return x - y

Complexity

Time: O(n × log_10 M), where n and M are the length of the array nums and the maximum value of the elements in the array, respectively
Space · auxiliary: O(1)

Pattern: Math and Number Theory

Find the closed form, the invariant, or the modular identity — and skip the loop entirely. LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Math.

The math and number theory guide has the Python template for the pattern and the 485 LeetCode problems that use it.

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Frequently asked questions

How hard is LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array?: LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array is rated Easy on LeetCode.
What is the time complexity of LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array?: The Python solution on this page runs in O(n × log_10 M), where n and M are the length of the array \textit{nums} and the maximum value of the elements in the array, respectively.
What is the space complexity of LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array?: The Python solution on this page uses O(1) auxiliary space.
What topics does LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array cover?: LeetCode 2535. Difference Between Element Sum and Digit Sum of an Array is tagged Array and Math 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...

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Transcribing...

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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."

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: Math and Number Theory

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