#2334
Subarray With Elements Greater Than Varying Threshold
HardArrayStackUnion-FindMonotonic StackSliding 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)
This approach uses a sliding window technique to efficiently find the longest subarray where all elements are greater than the threshold divided by the length of the subarray. It reduces unnecessary checks by maintaining a window and adjusting its size dynamically.
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Algorithm
4 steps- 1Step 1: Calculate the required value as threshold / k.
- 2Step 2: Initialize two pointers (left and right) to represent the current window of elements.
- 3Step 3: Expand the right pointer to include elements in the window until the window size exceeds k or an element is found that is not greater than the required value.
- 4Step 4: If the window size is exactly k and all elements are valid, return k. If not, move the left pointer to shrink the window and continue checking.
solution.py9 lines
1def findSubarray(nums, threshold, k):
2 required_value = threshold / k
3 left = 0
4 for right in range(len(nums)):
5 if nums[right] <= required_value:
6 left = right + 1
7 if right - left + 1 == k:
8 return k
9 return -1ℹ
Complexity note: This complexity is achieved because we traverse the array with a single pass using two pointers, making it linear in terms of the number of elements.
- 1The minimum element in the subarray must be greater than threshold / k for the entire subarray to be valid.
- 2Using a sliding window approach allows us to efficiently find valid subarrays without redundant checks.
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