64 lines
1.3 KiB
Go
64 lines
1.3 KiB
Go
// File: binary_tree_dfs.go
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// Created Time: 2022-11-26
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// Author: Reanon (793584285@qq.com)
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package chapter_tree
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import (
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. "github.com/krahets/hello-algo/pkg"
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)
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// preOrder 前序遍历
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func preOrder(root *TreeNode) (nums []int) {
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var preOrderHelper func(node *TreeNode)
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// 匿名函数
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preOrderHelper = func(node *TreeNode) {
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if node == nil {
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return
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}
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// 访问优先级：根结点 -> 左子树 -> 右子树
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nums = append(nums, node.Val)
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preOrderHelper(node.Left)
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preOrderHelper(node.Right)
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}
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// 函数调用
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preOrderHelper(root)
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return
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}
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// inOrder 中序遍历
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func inOrder(root *TreeNode) (nums []int) {
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var inOrderHelper func(node *TreeNode)
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// 匿名函数
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inOrderHelper = func(node *TreeNode) {
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if node == nil {
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return
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}
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// 访问优先级：左子树 -> 根结点 -> 右子树
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inOrderHelper(node.Left)
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nums = append(nums, node.Val)
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inOrderHelper(node.Right)
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}
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// 函数调用
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inOrderHelper(root)
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return
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}
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// postOrder 后序遍历
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func postOrder(root *TreeNode) (nums []int) {
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var postOrderHelper func(node *TreeNode)
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// 匿名函数
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postOrderHelper = func(node *TreeNode) {
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if node == nil {
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return
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}
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// 访问优先级：左子树 -> 右子树 -> 根结点
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postOrderHelper(node.Left)
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postOrderHelper(node.Right)
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nums = append(nums, node.Val)
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}
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// 函数调用
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postOrderHelper(root)
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return
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}
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