LC 0852 [E] Peak Index in a Mountain Array - ALawliet/algorithms GitHub Wiki

class Solution:
    def peakIndexInMountainArray(self, A: List[int]) -> int:
        n = len(A)
        L = 0
        R = n - 1 # -1 to check [m+1]
        while L < R:
            m = (L + R) // 2
            dnslope = A[m] > A[m+1] # \
            if not dnslope:
                L = m + 1
            else:
                R = m 
        return L