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class Solution:
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    def pathSum(self, root: Optional[TreeNode], targetSum: int) -> List[List[int]]:
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        res = []
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        def dfs(v, path, pathsum):
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            if not v:
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                return
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            path.append(v.val)
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            pathsum += v.val
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            if not v.left and not v.right and pathsum == targetSum:
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                res.append(path[:])
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            dfs(v.left, path, pathsum)
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            dfs(v.right, path, pathsum)
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            path.pop()
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        dfs(root, [], 0)
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        return res