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32 lines
1.2 KiB
HTML
32 lines
1.2 KiB
HTML
<p>A peak element is an element that is strictly greater than its neighbors.</p>
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<p>Given an integer array <code>nums</code>, find a peak element, and return its index. If the array contains multiple peaks, return the index to <strong>any of the peaks</strong>.</p>
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<p>You may imagine that <code>nums[-1] = nums[n] = -∞</code>.</p>
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<p>You must write an algorithm that runs in <code>O(log n)</code> time.</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> nums = [1,2,3,1]
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<strong>Output:</strong> 2
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<strong>Explanation:</strong> 3 is a peak element and your function should return the index number 2.</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> nums = [1,2,1,3,5,6,4]
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<strong>Output:</strong> 5
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<strong>Explanation:</strong> Your function can return either index number 1 where the peak element is 2, or index number 5 where the peak element is 6.</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 <= nums.length <= 1000</code></li>
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<li><code>-2<sup>31</sup> <= nums[i] <= 2<sup>31</sup> - 1</code></li>
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<li><code>nums[i] != nums[i + 1]</code> for all valid <code>i</code>.</li>
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</ul>
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