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47 lines
1.4 KiB
HTML
47 lines
1.4 KiB
HTML
<p>You may recall that an array <code>arr</code> is a <strong>mountain array</strong> if and only if:</p>
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<ul>
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<li><code>arr.length >= 3</code></li>
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<li>There exists some index <code>i</code> (<strong>0-indexed</strong>) with <code>0 < i < arr.length - 1</code> such that:
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<ul>
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<li><code>arr[0] < arr[1] < ... < arr[i - 1] < arr[i]</code></li>
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<li><code>arr[i] > arr[i + 1] > ... > arr[arr.length - 1]</code></li>
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</ul>
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</li>
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</ul>
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<p>Given an integer array <code>arr</code>, return <em>the length of the longest subarray, which is a mountain</em>. Return <code>0</code> if there is no mountain subarray.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> arr = [2,1,4,7,3,2,5]
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<strong>Output:</strong> 5
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<strong>Explanation:</strong> The largest mountain is [1,4,7,3,2] which has length 5.
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> arr = [2,2,2]
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<strong>Output:</strong> 0
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<strong>Explanation:</strong> There is no mountain.
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= arr.length <= 10<sup>4</sup></code></li>
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<li><code>0 <= arr[i] <= 10<sup>4</sup></code></li>
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</ul>
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<p> </p>
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<p><strong>Follow up:</strong></p>
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<ul>
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<li>Can you solve it using only one pass?</li>
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<li>Can you solve it in <code>O(1)</code> space?</li>
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</ul>
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