[Python] Trouble finding peak in mountain-like array with duplicates — binary search not...

`I'm trying to solve a problem where I need to find the peak element in a mountain-like array that may contain duplicates.

A peak element is one where the values first increase and then decrease (but plateaus like [6,6,6,6] may appear after the peak). Here's the code I’ve written:`

nums = [1, 3, 7, 6, 6, 6, 6, 6, 4, 3, 2, 1]

l = 0
r = len(nums) - 1

while l < r:
# Skip duplicates on the left
while l < r and nums[l] == nums[l + 1]:
l += 1
# Skip duplicates on the right
while l < r and nums[r] == nums[r - 1]:
r -= 1

m = (l + r) // 2

if nums[m] < nums[m + 1]:
l = m + 1
else:
r = m

print(nums[l]) # Expected output: 7


For the input:

[1, 3, 7, 6, 6, 6, 6, 6, 4, 3, 2, 1]


`I expect the peak to be 7, but the output is coming out as 6.

I suspect it’s due to the plateau confusing the binary search logic. How can I correctly handle duplicates, especially when there’s a long flat section after the peak?

Any suggestions on improving the binary search logic to correctly identify the peak in such cases would be really helpful.`

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