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* Fix is_empty() implementation in the stack and queue chapter * Update en/CONTRIBUTING.md * Remove "剩余" from the state definition of knapsack problem * Sync zh and zh-hant versions * Update the stylesheets of code tabs * Fix quick_sort.rb * Fix TS code * Update chapter_paperbook * Upload the manuscript of 0.1 section * Fix binary_tree_dfs.rb * Bug fixes * Update README * Update README * Update README * Update README.md * Update README * Sync zh and zh-hant versions * Bug fixes
63 lines
1.3 KiB
Ruby
63 lines
1.3 KiB
Ruby
=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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### 前序走訪 ###
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def pre_order(root)
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return if root.nil?
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# 訪問優先順序：根節點 -> 左子樹 -> 右子樹
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$res << root.val
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pre_order(root.left)
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pre_order(root.right)
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end
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### 中序走訪 ###
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def in_order(root)
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return if root.nil?
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# 訪問優先順序：左子樹 -> 根節點 -> 右子樹
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in_order(root.left)
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$res << root.val
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in_order(root.right)
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end
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### 後序走訪 ###
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def post_order(root)
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return if root.nil?
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# 訪問優先順序：左子樹 -> 右子樹 -> 根節點
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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__ == $0
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# 初始化二元樹
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# 這裡藉助了一個從陣列直接生成二元樹的函式
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root = arr_to_tree([1, 2, 3, 4, 5, 6, 7])
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puts "\n初始化二元樹\n\n"
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print_tree(root)
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# 前序走訪
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$res = []
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pre_order(root)
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puts "\n前序走訪的節點列印序列 = #{$res}"
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# 中序走訪
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$res.clear
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in_order(root)
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puts "\nn中序走訪的節點列印序列 = #{$res}"
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# 後序走訪
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$res.clear
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post_order(root)
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puts "\nn後序走訪的節點列印序列 = #{$res}"
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end
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