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43 lines
984 B
Python
43 lines
984 B
Python
"""
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File: preorder_traversal_iii_compact.py
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Created Time: 2023-04-15
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Author: krahets (krahets@163.com)
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"""
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import sys
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from pathlib import Path
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sys.path.append(str(Path(__file__).parent.parent))
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from modules import TreeNode, print_tree, list_to_tree
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def pre_order(root: TreeNode):
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"""前序遍历：例题三"""
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# 剪枝
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if root is None or root.val == 3:
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return
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# 尝试
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path.append(root)
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if root.val == 7:
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# 记录解
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res.append(list(path))
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pre_order(root.left)
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pre_order(root.right)
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# 回退
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path.pop()
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"""Driver Code"""
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if __name__ == "__main__":
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root = list_to_tree([1, 7, 3, 4, 5, 6, 7])
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print("\n初始化二叉树")
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print_tree(root)
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# 前序遍历
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path = list[TreeNode]()
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res = list[list[TreeNode]]()
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pre_order(root)
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print("\n输出所有根节点到节点 7 的路径，路径中不包含值为 3 的节点")
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for path in res:
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print([node.val for node in path])
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