Add Kotlin code for computational complexity (#1090)

* feat(kotlin):new kotlin support files * fix(kotlin): reviewed the formatting, comments and so on. * fix(kotlin): fix the indentation and format * feat(kotlin): Add kotlin code for the backtraking chapter. * fix(kotlin): fix incorrect output of preorder_traversal_iii_template.kt file * fix(kotlin): simplify kotlin codes * fix(kotlin): modify n_queens.kt for consistency. * feat(kotlin): add kotlin code for computational complexity. * fix(kotlin): remove iteration folder. * fix(kotlin): remove n_queens.kt file out of folder. * fix(kotlin): remove some folders. * style(kotlin): modified two chapters.
2025-11-02 12:58:42 +08:00 · 2024-02-27 17:04:57 +08:00
parent 92f82cbcca
commit 306dc019ef
15 changed files with 472 additions and 0 deletions
--- a/codes/kotlin/chapter_computational_complexity/space_complexity.kt
+++ b/codes/kotlin/chapter_computational_complexity/space_complexity.kt
@ -0,0 +1,109 @@
+/**
+ * File: space_complexity.kt
+ * Created Time: 2024-01-25
+ * Author: curtishd (1023632660@qq.com)
+ */
+
+package chapter_computational_complexity.space_complexity
+
+import utils.ListNode
+import utils.TreeNode
+import utils.printTree
+
+/* 函数 */
+fun function(): Int {
+    // 执行某些操作
+    return 0
+}
+
+/* 常数阶 */
+fun constant(n: Int) {
+    // 常量、变量、对象占用 O(1) 空间
+    val a = 0
+    var b = 0
+    val nums = Array(10000) { 0 }
+    val node = ListNode(0)
+    // 循环中的变量占用 O(1) 空间
+    for (i in 0..<n) {
+        val c = 0
+    }
+    // 循环中的函数占用 O(1) 空间
+    for (i in 0..<n) {
+        function()
+    }
+}
+
+/* 线性阶 */
+fun linear(n: Int) {
+    // 长度为 n 的数组占用 O(n) 空间
+    val nums = Array(n) { 0 }
+    // 长度为 n 的列表占用 O(n) 空间
+    val nodes = mutableListOf<ListNode>()
+    for (i in 0..<n) {
+        nodes.add(ListNode(i))
+    }
+    // 长度为 n 的哈希表占用 O(n) 空间
+    val map = mutableMapOf<Int, String>()
+    for (i in 0..<n) {
+        map[i] = i.toString()
+    }
+}
+
+/* 线性阶（递归实现） */
+fun linearRecur(n: Int) {
+    println("递归 n = $n")
+    if (n == 1)
+        return
+    linearRecur(n - 1)
+}
+
+/* 平方阶 */
+fun quadratic(n: Int) {
+    // 矩阵占用 O(n^2) 空间
+    val numMatrix: Array<Array<Int>?> = arrayOfNulls(n)
+    // 二维列表占用 O(n^2) 空间
+    val numList: MutableList<MutableList<Int>> = arrayListOf()
+    for (i in 0..<n) {
+        val tmp = mutableListOf<Int>()
+        for (j in 0..<n) {
+            tmp.add(0)
+        }
+        numList.add(tmp)
+    }
+}
+
+/* 平方阶（递归实现） */
+tailrec fun quadraticRecur(n: Int): Int {
+    if (n <= 0)
+        return 0
+    // 数组 nums 长度为 n, n-1, ..., 2, 1
+    val nums = Array(n) { 0 }
+    println("递归 n = $n 中的 nums 长度 = ${nums.size}")
+    return quadraticRecur(n - 1)
+}
+
+/* 指数阶（建立满二叉树） */
+fun buildTree(n: Int): TreeNode? {
+    if (n == 0)
+        return null
+    val root = TreeNode(0)
+    root.left = buildTree(n - 1)
+    root.right = buildTree(n - 1)
+    return root
+}
+
+/* Driver Code */
+fun main() {
+    val n = 5
+    // 常数阶
+    constant(n)
+    // 线性阶
+    linear(n)
+    linearRecur(n)
+    // 平方阶
+    quadratic(n)
+    quadraticRecur(n)
+    // 指数阶
+    val root: TreeNode? = buildTree(n)
+    printTree(root)
+}