852.md

Peak Index in a Mountain Array

Description

link

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Solution

• See Code

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Code

O(log(n))

class Solution:
    def peakIndexInMountainArray(self, A: List[int]) -> int:
        l, r = 0, len(A) - 1
        while l < r:
            m = (l + r) // 2
            if A[m] < A[m+1]:
                l = m + 1
            else:
                r = m
        return l