From 5617f8246f4983500b5b0ffcfd4db43f9f09c313 Mon Sep 17 00:00:00 2001 From: Cathay Date: Thu, 15 Dec 2022 16:41:47 +0800 Subject: [PATCH 1/2] feat(space_complexity): add the Go code to space complexity docs (Chapter of Computational Complexity) --- .../space_complexity.go | 123 ++++++++++++++++ .../space_complexity_test.go | 30 ++++ .../space_complexity.md | 137 +++++++++++++++++- 3 files changed, 283 insertions(+), 7 deletions(-) create mode 100644 codes/go/chapter_computational_complexity/space_complexity.go create mode 100644 codes/go/chapter_computational_complexity/space_complexity_test.go diff --git a/codes/go/chapter_computational_complexity/space_complexity.go b/codes/go/chapter_computational_complexity/space_complexity.go new file mode 100644 index 000000000..77780ae04 --- /dev/null +++ b/codes/go/chapter_computational_complexity/space_complexity.go @@ -0,0 +1,123 @@ +// File: space_complexity.go +// Created Time: 2022-12-15 +// Author: cathay (cathaycchen@gmail.com) + +package chapter_computational_complexity + +import ( + "fmt" + "strconv" +) + +/* Node 结构体 */ +type Node struct { + val int + next *Node +} + +/* TreeNode 二叉树 */ +type TreeNode struct { + val int + left *TreeNode + right *TreeNode +} + +/* 创建 Node 结构体 */ +func newNode(val int) *Node { + return &Node{val: val} +} + +/* 创建 TreeNode 结构体 */ +func newTreeNode(val int) *TreeNode { + return &TreeNode{val: val} +} + +/* 输出二叉树 */ +func printTree(root *TreeNode) { + if root == nil { + return + } + fmt.Println(root.val) + printTree(root.left) + printTree(root.right) +} + +/* 函数（或称方法）*/ +func function() int { + // do something... + return 0 +} + +/* 常数阶 */ +func spaceConstant(n int) { + // 常量、变量、对象占用 O(1) 空间 + const a = 0 + b := 0 + nums := make([]int, 10000) + ListNode := newNode(0) + // 循环中的变量占用 O(1) 空间 + var c int + for i := 0; i < n; i++ { + c = 0 + } + // 循环中的函数占用 O(1) 空间 + for i := 0; i < n; i++ { + function() + } + fmt.Println(a, b, nums, c, ListNode) +} + +/* 线性阶 */ +func spaceLinear(n int) { + // 长度为 n 的数组占用 O(n) 空间 + _ = make([]int, n) + // 长度为 n 的列表占用 O(n) 空间 + var nodes []*Node + for i := 0; i < n; i++ { + nodes = append(nodes, newNode(i)) + } + // 长度为 n 的哈希表占用 O(n) 空间 + m := make(map[int]string, n) + for i := 0; i < n; i++ { + m[i] = strconv.Itoa(i) + } +} + +/* 线性阶（递归实现） */ +func spaceLinearRecur(n int) { + fmt.Println("递归 n =", n) + if n == 1 { + return + } + spaceLinearRecur(n - 1) +} + +/* 平方阶 */ +func spaceQuadratic(n int) { + // 矩阵占用 O(n^2) 空间 + numMatrix := make([][]int, n) + for i := 0; i < n; i++ { + numMatrix[i] = make([]int, n) + } +} + +/* 平方阶（递归实现） */ +func spaceQuadraticRecur(n int) int { + if n <= 0 { + return 0 + } + nums := make([]int, n) + fmt.Printf("递归 n = %d 中的 nums 长度 = %d \n", n, len(nums)) + return spaceQuadraticRecur(n - 1) +} + +/* 指数阶（建立满二叉树） */ +func buildTree(n int) *TreeNode { + if n == 0 { + return nil + } + root := newTreeNode(0) + root.left = buildTree(n - 1) + root.right = buildTree(n - 1) + return root +} diff --git a/codes/go/chapter_computational_complexity/space_complexity_test.go b/codes/go/chapter_computational_complexity/space_complexity_test.go new file mode 100644 index 000000000..9e8237235 --- /dev/null +++ b/codes/go/chapter_computational_complexity/space_complexity_test.go @@ -0,0 +1,30 @@ +// File: space_complexity_test.go +// Created Time: 2022-12-15 +// Author: cathay (cathaycchen@gmail.com) + +package chapter_computational_complexity + +import ( + "testing" +) + +func TestSpaceComplexity(t *testing.T) { + /* ======= Test Case ======= */ + n := 5 + + /* ====== Driver Code ====== */ + // 常数阶 + spaceConstant(n) + + // 线性阶 + spaceLinear(n) + spaceLinearRecur(n) + + // 平方阶 + spaceQuadratic(n) + spaceQuadraticRecur(n) + + // 指数阶 + root := buildTree(n) + printTree(root) +} diff --git a/docs/chapter_computational_complexity/space_complexity.md b/docs/chapter_computational_complexity/space_complexity.md index 95ecb7b4b..de623e22e 100644 --- a/docs/chapter_computational_complexity/space_complexity.md +++ b/docs/chapter_computational_complexity/space_complexity.md @@ -102,7 +102,30 @@ comments: true === "Go" ```go title="" + /* 结构体 */ + type Node struct { + val int + next *Node + } + + /* 创建 Node 结构体 */ + func newNode(val int) *Node { + return &Node{val: val} + } + + /* 函数（或称方法）*/ + func function() int { + // do something... + return 0 + } + func algorithm(n int) int { // 输入数据 + const a = 0 // 暂存数据（常量） + b := 0 // 暂存数据（变量） + newNode(0) // 暂存数据（对象） + c := function() // 栈帧空间（调用函数） + return a + b + c // 输出数据 + } ``` === "JavaScript" @@ -173,7 +196,15 @@ comments: true === "Go" ```go title="" - + func algorithm1(n int) { + a := 0 // O(1) + b := make([]int, 10000) // O(1) + var nums []int + if n > 10 { + nums = make([]int, 10000) // O(n) + } + fmt.Println(a, b, nums) + } ``` === "JavaScript" @@ -263,7 +294,25 @@ comments: true === "Go" ```go title="" - + func function() int { + // do something + return 0 + } + + /* 循环 O(1) */ + func loop(n int) { + for i := 0; i < n; i++ { + function() + } + } + + /* 递归 O(n) */ + func recur(n int) { + if n == 1 { + return + } + recur(n - 1) + } ``` === "JavaScript" @@ -377,7 +426,24 @@ $$ === "Go" ```go title="space_complexity.go" - + /* 常数阶 */ + func spaceConstant(n int) { + // 常量、变量、对象占用 O(1) 空间 + const a = 0 + b := 0 + nums := make([]int, 10000) + ListNode := newNode(0) + // 循环中的变量占用 O(1) 空间 + var c int + for i := 0; i < n; i++ { + c = 0 + } + // 循环中的函数占用 O(1) 空间 + for i := 0; i < n; i++ { + function() + } + fmt.Println(a, b, nums, c, ListNode) + } ``` === "JavaScript" @@ -464,7 +530,21 @@ $$ === "Go" ```go title="space_complexity.go" - + /* 线性阶 */ + func spaceLinear(n int) { + // 长度为 n 的数组占用 O(n) 空间 + _ = make([]int, n) + // 长度为 n 的列表占用 O(n) 空间 + var nodes []*Node + for i := 0; i < n; i++ { + nodes = append(nodes, newNode(i)) + } + // 长度为 n 的哈希表占用 O(n) 空间 + m := make(map[int]string, n) + for i := 0; i < n; i++ { + m[i] = strconv.Itoa(i) + } + } ``` === "JavaScript" @@ -528,7 +608,14 @@ $$ === "Go" ```go title="space_complexity.go" - + /* 线性阶（递归实现） */ + func spaceLinearRecur(n int) { + fmt.Println("递归 n =", n) + if n == 1 { + return + } + spaceLinearRecur(n - 1) + } ``` === "JavaScript" @@ -611,7 +698,14 @@ $$ === "Go" ```go title="space_complexity.go" - + /* 平方阶 */ + func spaceQuadratic(n int) { + // 矩阵占用 O(n^2) 空间 + numMatrix := make([][]int, n) + for i := 0; i < n; i++ { + numMatrix[i] = make([]int, n) + } + } ``` === "JavaScript" @@ -678,7 +772,15 @@ $$ === "Go" ```go title="space_complexity.go" - + /* 平方阶（递归实现） */ + func spaceQuadraticRecur(n int) int { + if n <= 0 { + return 0 + } + nums := make([]int, n) + fmt.Printf("递归 n = %d 中的 nums 长度 = %d \n", n, len(nums)) + return spaceQuadraticRecur(n - 1) + } ``` === "JavaScript" @@ -754,7 +856,28 @@ $$ === "Go" ```go title="space_complexity.go" + /* TreeNode 二叉树 */ + type TreeNode struct { + val int + left *TreeNode + right *TreeNode + } + + /* 创建 TreeNode 结构体 */ + func newTreeNode(val int) *TreeNode { + return &TreeNode{val: val} + } + /* 指数阶（建立满二叉树） */ + func buildTree(n int) *TreeNode { + if n == 0 { + return nil + } + root := newTreeNode(0) + root.left = buildTree(n - 1) + root.right = buildTree(n - 1) + return root + } ``` === "JavaScript" From ae37e902a9b84df6500027076b3af3e2ffec313f Mon Sep 17 00:00:00 2001 From: Yudong Jin Date: Thu, 15 Dec 2022 22:38:18 +0800 Subject: [PATCH 2/2] Update space_complexity.md --- .../space_complexity.md | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) diff --git a/docs/chapter_computational_complexity/space_complexity.md b/docs/chapter_computational_complexity/space_complexity.md index de623e22e..6c876a3e6 100644 --- a/docs/chapter_computational_complexity/space_complexity.md +++ b/docs/chapter_computational_complexity/space_complexity.md @@ -196,7 +196,7 @@ comments: true === "Go" ```go title="" - func algorithm1(n int) { + func algorithm(n int) { a := 0 // O(1) b := make([]int, 10000) // O(1) var nums []int @@ -856,18 +856,6 @@ $$ === "Go" ```go title="space_complexity.go" - /* TreeNode 二叉树 */ - type TreeNode struct { - val int - left *TreeNode - right *TreeNode - } - - /* 创建 TreeNode 结构体 */ - func newTreeNode(val int) *TreeNode { - return &TreeNode{val: val} - } - /* 指数阶（建立满二叉树） */ func buildTree(n int) *TreeNode { if n == 0 {