27 lines
793 B
Markdown
27 lines
793 B
Markdown
You may recall that an array `arr` is a mountain array if and only if:
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* `arr.length >= 3`
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* There exists some index `i` (0-indexed) with `0 < i < arr.length - 1` such that:
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* `arr[0] < arr[1] < ... < arr[i - 1] < arr[i]`
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* `arr[i] > arr[i + 1] > ... > arr[arr.length - 1]`
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Given an integer array `arr`, return _the length of the longest subarray, which is a mountain_. Return `0` if there is no mountain subarray.
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Example 1:
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Input: arr = [2,1,4,7,3,2,5] Output: 5 Explanation: The largest mountain is [1,4,7,3,2] which has length 5.
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Example 2:
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Input: arr = [2,2,2] Output: 0 Explanation: There is no mountain.
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Constraints:
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* `1 <= arr.length <= 104`
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* `0 <= arr[i] <= 104`
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Follow up:
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* Can you solve it using only one pass?
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* Can you solve it in `O(1)` space?
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