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60 lines
1.5 KiB
Python
60 lines
1.5 KiB
Python
"""
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162. Find Peak Element
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Difficulty: Medium
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https://leetcode.com/problems/find-peak-element/
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──────────────────────────────────────────────────
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A peak element is an element that is strictly greater than its
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neighbors.
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Given a 0-indexed integer array nums, find a peak element, and return
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its index. If the array contains multiple peaks, return the index to
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any of the peaks.
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You may imagine that nums[-1] = nums[n] = -∞. In other words,
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an element is always considered to be strictly greater than a neighbor
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that is outside the array.
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You must write an algorithm that runs in O(log n) time.
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Example 1:
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Input: nums = [1,2,3,1]
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Output: 2
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Explanation: 3 is a peak element and your function should return the
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index number 2.
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Example 2:
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Input: nums = [1,2,1,3,5,6,4]
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Output: 5
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Explanation: Your function can return either index number 1 where the
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peak element is 2, or index number 5 where the peak element is 6.
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Constraints:
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• 1 <= nums.length <= 1000
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• -2^31 <= nums[i] <= 2^31 - 1
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• nums[i] != nums[i + 1] for all valid i.
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"""
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class Solution:
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def findPeakElement(self, nums: list[int]) -> int:
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left, right = 0, len(nums) - 1
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while left < right:
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mid = (left + right) // 2
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if nums[mid] < nums[mid + 1]:
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left = mid + 1
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else:
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right = mid
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return left
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