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63 lines
1.3 KiB
63 lines
1.3 KiB
=begin
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File: binary_tree_dfs.rb
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Created Time: 2024-04-18
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Author: Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
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=end
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require_relative '../utils/tree_node'
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require_relative '../utils/print_util'
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### 前序遍历 ###
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def pre_order(root)
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return if root.nil?
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# 访问优先级：根节点 -> 左子树 -> 右子树
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$res << root.val
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pre_order(root.left)
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pre_order(root.right)
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end
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### 中序遍历 ###
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def in_order(root)
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return if root.nil?
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# 访问优先级：左子树 -> 根节点 -> 右子树
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in_order(root.left)
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$res << root.val
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in_order(root.right)
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end
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### 后序遍历 ###
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def post_order(root)
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return if root.nil?
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# 访问优先级：左子树 -> 右子树 -> 根节点
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post_order(root.left)
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post_order(root.right)
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$res << root.val
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end
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### Driver Code ###
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if __FILE__ == $0
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# 初始化二叉树
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# 这里借助了一个从数组直接生成二叉树的函数
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root = arr_to_tree([1, 2, 3, 4, 5, 6, 7])
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puts "\n初始化二叉树\n\n"
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print_tree(root)
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# 前序遍历
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$res = []
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pre_order(root)
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puts "\n前序遍历的节点打印序列 = #{$res}"
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# 中序遍历
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$res.clear
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in_order(root)
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puts "\nn中序遍历的节点打印序列 = #{$res}"
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# 后序遍历
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$res.clear
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post_order(root)
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puts "\nn后序遍历的节点打印序列 = #{$res}"
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end
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