feat(go): support basic pkg

pull/20/head
reanon 2 years ago
parent daf25d5e64
commit 07a359484b

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// File: linear_search.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package chapter_searching
import (
. "github.com/krahets/hello-algo/pkg"
)
// linerSearchArray 线性查找(数组)
func linerSearchArray(nums []int, target int) int {
// 遍历数组
for i := 0; i < len(nums); i++ {
if nums[i] == target {
// 找到目标元素,返回其索引
return i
}
}
// 未找到目标元素,返回 -1
return -1
}
// linerSearchLinkedList 线性查找(链表)
func linerSearchLinkedList(node *ListNode, target int) *ListNode {
// 遍历链表
for node != nil {
if node.Val == target {
return node
}
node = node.Next
}
// 未找到目标元素,返回 nil
return nil
}

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// File: linear_search_test.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package chapter_searching
import (
. "github.com/krahets/hello-algo/pkg"
"testing"
)
func TestLinearSearch(t *testing.T) {
target := 3
nums := []int{1, 5, 3, 2, 4, 7, 5, 9, 10, 8}
// 在数组中执行线性查找
index := linerSearchArray(nums, target)
t.Log("目标元素 3 的索引 = ", index)
// 在链表中执行线性查找
head := ArrayToLinkedListLinkedList(nums)
node := linerSearchLinkedList(head, target)
t.Log("目标结点值 3 的对应结点对象为 ", node)
}

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// File: binary_search_tree.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package chapter_tree
import (
. "github.com/krahets/hello-algo/pkg"
"sort"
)
type BinarySearchTree struct {
root *TreeNode
}
func NewBinarySearchTree(nums []int) *BinarySearchTree {
// 排序数组
sort.Ints(nums)
return nil
}

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// File: binary_tree.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package chapter_tree
import (
. "github.com/krahets/hello-algo/pkg"
)
type BinaryTree struct {
root *TreeNode
}
func NewBinaryTree(node *TreeNode) *BinaryTree {
return &BinaryTree{
root: node,
}
}
func (tree *BinaryTree) Print() {
PrintTree(tree.root)
}

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// File: binary_tree_test.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package chapter_tree
import (
. "github.com/krahets/hello-algo/pkg"
"testing"
)
func TestBinaryTree(t *testing.T) {
/* 初始化二叉树 */
// 初始化节点
n1 := NewTreeNode(1)
n2 := NewTreeNode(2)
n3 := NewTreeNode(3)
n4 := NewTreeNode(4)
n5 := NewTreeNode(5)
tree := NewBinaryTree(n1)
n1.Left = n2
n1.Right = n3
n2.Left = n4
n2.Right = n5
t.Log("初始化二叉树")
tree.Print()
/* 插入与删除结点 */
p := NewTreeNode(0)
n1.Left = p
p.Left = n2
t.Log("插入结点 P 后")
tree.Print()
// 删除结点
n1.Left = n2
t.Log("删除结点 P 后")
tree.Print()
}

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// File: list_node.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package pkg
import (
"fmt"
"strconv"
"strings"
)
// ListNode Definition for a singly-linked list node
type ListNode struct {
Next *ListNode
Val int
}
// NewListNode Generate a list node with an val
func NewListNode(v int) *ListNode {
return &ListNode{
Next: nil,
Val: v,
}
}
// ArrayToLinkedListLinkedList Generate a linked list with an array
func ArrayToLinkedListLinkedList(arr []int) *ListNode {
// dummy header of linked list
dummy := NewListNode(0)
node := dummy
for _, val := range arr {
node.Next = NewListNode(val)
node = node.Next
}
return dummy.Next
}
// GetListNode Get a list node with specific value from a linked list
func GetListNode(node *ListNode, val int) *ListNode {
for node != nil && node.Val != val {
node = node.Next
}
return node
}
// PrintLinkedList Print a linked list
func PrintLinkedList(node *ListNode) {
if node == nil {
return
}
var builder strings.Builder
for node.Next != nil {
builder.WriteString(strconv.Itoa(node.Val) + " -> ")
node = node.Next
}
builder.WriteString(strconv.Itoa(node.Val))
fmt.Println(builder.String())
}

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// File: list_node_test.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package pkg
import "testing"
func TestListNode(t *testing.T) {
arr := []int{2, 3, 5, 6, 7}
head := ArrayToLinkedListLinkedList(arr)
PrintLinkedList(head)
node := GetListNode(head, 5)
t.Log("Find node: ", node.Val)
}

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// File: tree_node.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package pkg
import (
"container/list"
"fmt"
)
type TreeNode struct {
Val int
Left *TreeNode
Right *TreeNode
}
func NewTreeNode(v int) *TreeNode {
return &TreeNode{
Left: nil,
Right: nil,
Val: v,
}
}
// ArrayToTree Generate a binary tree with an array
func ArrayToTree(arr []int) *TreeNode {
if len(arr) <= 0 {
return nil
}
root := NewTreeNode(arr[0])
// Let container.list as queue
queue := list.New()
queue.PushBack(root)
i := 1
for queue.Len() > 0 {
// poll
node := queue.Remove(queue.Front()).(*TreeNode)
if i < len(arr) {
node.Left = NewTreeNode(arr[i])
queue.PushBack(node.Left)
i++
}
if i < len(arr) {
node.Right = NewTreeNode(arr[i])
queue.PushBack(node.Right)
i++
}
}
return root
}
// TreeToArray Serialize a binary tree to a list
func TreeToArray(root *TreeNode) []int {
if root == nil {
return []int{}
}
arr := make([]int, 16)
queue := list.New()
queue.PushBack(root)
for queue.Len() > 0 {
node := queue.Remove(queue.Front()).(*TreeNode)
if node != nil {
arr = append(arr, node.Val)
queue.PushBack(node.Left)
queue.PushBack(node.Right)
} else {
arr = append(arr, -1)
}
}
return arr
}
// PrintTree Print a binary tree
func PrintTree(root *TreeNode) {
PrintTreeHelper(root, nil, false)
}
// PrintTreeHelper Help to print a binary tree, hide more details
// This tree printer is borrowed from TECHIE DELIGHT
// https://www.techiedelight.com/c-program-print-binary-tree/
func PrintTreeHelper(root *TreeNode, prev *trunk, isLeft bool) {
if root == nil {
return
}
prevStr := " "
trunk := newTrunk(prev, prevStr)
PrintTreeHelper(root.Right, trunk, true)
if prev == nil {
trunk.str = "———"
} else if isLeft {
trunk.str = "/———"
prevStr = " |"
} else {
trunk.str = "\\———"
prev.str = prevStr
}
showTrunk(trunk)
fmt.Println(root.Val)
if prev != nil {
prev.str = prevStr
}
trunk.str = " |"
PrintTreeHelper(root.Left, trunk, false)
}
// trunk Help to Print tree structure
type trunk struct {
prev *trunk
str string
}
func newTrunk(prev *trunk, str string) *trunk {
return &trunk{
prev: prev,
str: str,
}
}
func showTrunk(t *trunk) {
if t == nil {
return
}
showTrunk(t.prev)
fmt.Print(t.str)
}

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// File: tree_node_test.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package pkg
import "testing"
func TestTreeNode(t *testing.T) {
arr := []int{2, 3, 5, 6, 7}
node := ArrayToTree(arr)
// print tree
PrintTree(node)
}
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