hello-algo/zh-hant/codes/kotlin/chapter_tree/binary_tree_dfs.kt
Yudong Jin b2f0d4603d
Many bug fixes and improvements (#1270)
* Add Ruby and Kotlin icons
Add the avatar of @curtishd

* Update README

* Synchronize zh-hant and zh versions.

* Translate the pythontutor blocks to traditional Chinese

* Fix en/mkdocs.yml

* Update the landing page of the en version.

* Fix the Dockerfile

* Refine the en landingpage

* Fix en landing page

* Reset the README.md
2024-04-11 20:18:19 +08:00

64 lines
No EOL
1.5 KiB
Kotlin

/**
* File: binary_tree_dfs.kt
* Created Time: 2024-01-25
* Author: curtishd (1023632660@qq.com)
*/
package chapter_tree
import utils.TreeNode
import utils.printTree
// 初始化串列,用於儲存走訪序列
var list = mutableListOf<Int>()
/* 前序走訪 */
fun preOrder(root: TreeNode?) {
if (root == null) return
// 訪問優先順序:根節點 -> 左子樹 -> 右子樹
list.add(root._val)
preOrder(root.left)
preOrder(root.right)
}
/* 中序走訪 */
fun inOrder(root: TreeNode?) {
if (root == null) return
// 訪問優先順序:左子樹 -> 根節點 -> 右子樹
inOrder(root.left)
list.add(root._val)
inOrder(root.right)
}
/* 後序走訪 */
fun postOrder(root: TreeNode?) {
if (root == null) return
// 訪問優先順序:左子樹 -> 右子樹 -> 根節點
postOrder(root.left)
postOrder(root.right)
list.add(root._val)
}
/* Driver Code */
fun main() {
/* 初始化二元樹 */
// 這裡藉助了一個從陣列直接生成二元樹的函式
val root = TreeNode.listToTree(mutableListOf(1, 2, 3, 4, 5, 6, 7))
println("\n初始化二元樹\n")
printTree(root)
/* 前序走訪 */
list.clear()
preOrder(root)
println("\n前序走訪的節點列印序列 = $list")
/* 中序走訪 */
list.clear()
inOrder(root)
println("\n中序走訪的節點列印序列 = $list")
/* 後序走訪 */
list.clear()
postOrder(root)
println("\n後序走訪的節點列印序列 = $list")
}