102 lines
2.1 KiB
Go
102 lines
2.1 KiB
Go
// File: array_binary_tree.go
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// Created Time: 2023-07-24
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// Author: Reanon (793584285@qq.com)
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package chapter_tree
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/* Array-based binary tree class */
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type arrayBinaryTree struct {
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tree []any
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}
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/* Constructor */
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func newArrayBinaryTree(arr []any) *arrayBinaryTree {
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return &arrayBinaryTree{
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tree: arr,
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}
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}
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/* List capacity */
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func (abt *arrayBinaryTree) size() int {
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return len(abt.tree)
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}
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/* Get the value of the node at index i */
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func (abt *arrayBinaryTree) val(i int) any {
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// If the index is out of bounds, return null, representing an empty spot
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if i < 0 || i >= abt.size() {
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return nil
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}
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return abt.tree[i]
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}
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/* Get the index of the left child of the node at index i */
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func (abt *arrayBinaryTree) left(i int) int {
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return 2*i + 1
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}
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/* Get the index of the right child of the node at index i */
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func (abt *arrayBinaryTree) right(i int) int {
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return 2*i + 2
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}
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/* Get the index of the parent of the node at index i */
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func (abt *arrayBinaryTree) parent(i int) int {
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return (i - 1) / 2
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}
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/* Level-order traversal */
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func (abt *arrayBinaryTree) levelOrder() []any {
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var res []any
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// Traverse array
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for i := 0; i < abt.size(); i++ {
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if abt.val(i) != nil {
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res = append(res, abt.val(i))
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}
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}
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return res
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}
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/* Depth-first traversal */
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func (abt *arrayBinaryTree) dfs(i int, order string, res *[]any) {
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// If it is an empty spot, return
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if abt.val(i) == nil {
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return
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}
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// Pre-order traversal
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if order == "pre" {
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*res = append(*res, abt.val(i))
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}
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abt.dfs(abt.left(i), order, res)
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// In-order traversal
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if order == "in" {
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*res = append(*res, abt.val(i))
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}
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abt.dfs(abt.right(i), order, res)
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// Post-order traversal
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if order == "post" {
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*res = append(*res, abt.val(i))
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}
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}
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/* Pre-order traversal */
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func (abt *arrayBinaryTree) preOrder() []any {
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var res []any
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abt.dfs(0, "pre", &res)
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return res
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}
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/* In-order traversal */
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func (abt *arrayBinaryTree) inOrder() []any {
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var res []any
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abt.dfs(0, "in", &res)
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return res
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}
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/* Post-order traversal */
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func (abt *arrayBinaryTree) postOrder() []any {
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var res []any
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abt.dfs(0, "post", &res)
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return res
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}
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