#2024
Maximize the Confusion of an Exam
MediumStringBinary SearchSliding WindowPrefix SumSliding WindowTwo Pointers
Approaches
Brute ForceOptimal
Complexity Comparison
| Brute Force | Optimal Solution★ | |
|---|---|---|
| Time | O(n²) | O(n) |
| Space | O(1) | O(1) |
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Intuition
Time O(n)Space O(1)
We can use a sliding window approach to maintain a window of characters that can be converted with at most k changes. This allows us to efficiently find the maximum length of consecutive characters.
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Algorithm
4 steps- 1Step 1: Initialize two pointers (left and right) and a count for changes.
- 2Step 2: Expand the right pointer to include more characters until the number of changes exceeds k.
- 3Step 3: If changes exceed k, move the left pointer to reduce the window size until changes are within k.
- 4Step 4: Keep track of the maximum length of the window during this process.
solution.py18 lines
1def maxConsecutiveAnswers(answerKey, k):
2 left = 0
3 max_length = 0
4 count_T = 0
5 count_F = 0
6 for right in range(len(answerKey)):
7 if answerKey[right] == 'T':
8 count_T += 1
9 else:
10 count_F += 1
11 while min(count_T, count_F) > k:
12 if answerKey[left] == 'T':
13 count_T -= 1
14 else:
15 count_F -= 1
16 left += 1
17 max_length = max(max_length, right - left + 1)
18 return max_lengthℹ
Complexity note: This complexity is linear because we only traverse the string once with two pointers, adjusting the window size dynamically.
- 1Using a sliding window helps efficiently manage the number of changes needed.
- 2The problem can be viewed as finding the longest segment of a string with at most k changes.
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