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class Solution:
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    def partitionDisjoint(self, nums: List[int]) -> int:
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        prefix = [nums[0] for _ in range(len(nums))]
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        suffix = [nums[-1] for _ in range(len(nums))]
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        for i in range(1, len(nums)):
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            prefix[i] = max(prefix[i - 1], nums[i - 1])
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        for i in range(len(nums) - 2, -1, -1):
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            suffix[i] = min(suffix[i + 1], nums[i + 1])
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        for i in range(0, len(nums) - 1):
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            if prefix[i] <= suffix[i]:
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                return i + 1