Find the Minimum and Maximum Number of Nodes Between Critical Points LeetCode solution in Python

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# Runtime: 687 ms (Top 71.4%) | Memory: 56.78 MB (Top 82.0%)
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class Solution:
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    def nodesBetweenCriticalPoints(self, head: Optional[ListNode]) -> List[int]:
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        idx, i = [], 1
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        prev, cur = head, head.next
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        while cur and cur.next:
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            if prev.val < cur.val > cur.next.val or prev.val > cur.val < cur.next.val:
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                idx.append(i)
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            prev = cur
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            cur = cur.next
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            i += 1
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        if len(idx) < 2:
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            return [-1, -1]
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        minDist = min(j - i for i, j in pairwise(idx))
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        maxDist = idx[-1] - idx[0]
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        return [minDist, maxDist]