Brainteaser LeetCode Problems: 16 Python Solutions

Brainteaser problems by difficulty

Problems with a complete Python solution are listed first, then by ascending problem number.

Easy (2)

Easy problems
No.	Problem	Topics
0292	Nim Game	Brainteaser, Math, Game Theory
1025	Divisor Game	Brainteaser, Math, Dynamic Programming +1

Medium (13)

Medium problems
No.	Problem	Topics
0319	Bulb Switcher	Brainteaser, Math
1033	Moving Stones Until Consecutive	Brainteaser, Math
1227	Airplane Seat Assignment Probability	Brainteaser, Math, Dynamic Programming +1
1503	Last Moment Before All Ants Fall Out of a Plank	Brainteaser, Array, Simulation
2396	Strictly Palindromic Number	Brainteaser, Math, Two Pointers
2419	Longest Subarray With Maximum Bitwise AND	Bit Manipulation, Brainteaser, Array
2425	Bitwise XOR of All Pairings	Bit Manipulation, Brainteaser, Array
2568	Minimum Impossible OR	Bit Manipulation, Brainteaser, Array
2731	Movement of Robots	Brainteaser, Array, Prefix Sum +1
2745	Construct the Longest New String	Greedy, Brainteaser, Math +1
2749	Minimum Operations to Make the Integer Zero	Bit Manipulation, Brainteaser, Enumeration
1908	Game of NimPremium	Bit Manipulation, Brainteaser, Array +3
2505	Bitwise OR of All Subsequence SumsPremium	Bit Manipulation, Brainteaser, Array +2

Hard (1)

Hard problems
No.	Problem	Topics
0810	Chalkboard XOR Game	Bit Manipulation, Brainteaser, Array +2

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python

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

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.

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GPT-6.1 Terra

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python

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

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 TerraClear chat

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.

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 TerraClear chat

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

Brainteaser LeetCode Problems: All 16,
With Python Solutions

Brainteaser problems by difficulty

Easy (2)

Medium (13)

Hard (1)

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Brainteaser problems by difficulty

Easy (2)2

Medium (13)13

Hard (1)1

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Easy (2)

Medium (13)

Hard (1)