feat: update trie

Author: treeforest

README.md

@@ -19,6 +19,7 @@
 ## 树 tree
 * [BinaryTree](https://github.com/treeforest/algorithm/tree/master/tree/BinaryTree): 二叉树(二叉搜索树)
 * [RBTree](https://github.com/treeforest/algorithm/tree/master/tree/RBTree): 红黑树(实现有序集合 K-V 的存储)
+* [Trie](https://github.com/treeforest/algorithm/tree/master/tree/Trie): 前缀树trie
 
 ## 图论 graph
 * [AdjacencyMatrix](https://github.com/treeforest/algorithm/tree/master/Graph/AdjacencyMatrix): 图的邻接矩阵存储(模板实现)

tree/Trie/go.mod

@@ -0,0 +1,5 @@
+module github.com/treeforest/algorithm/tree/Trie
+
+go 1.15
+
+require github.com/stretchr/testify v1.7.0

tree/Trie/go.sum

@@ -0,0 +1,6 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

tree/Trie/trie.go

@@ -0,0 +1,56 @@
+package trie
+
+// trieNode trie节点
+type TrieNode struct {
+	// data 当前节点存储的值
+	data rune
+	// isEnd 标记一个关键字结尾
+	isEnd bool
+	// children 该节点的子节点
+	children map[rune]*TrieNode
+}
+
+func NewTrieNode(data rune) *TrieNode {
+	return &TrieNode{
+		data:     data,
+		isEnd:    false,
+		children: make(map[rune]*TrieNode),
+	}
+}
+
+// Trie trie树
+type Trie struct {
+	// root trie根节点
+	root *TrieNode
+}
+
+func NewTrie() *Trie {
+	return &Trie{root: NewTrieNode(rune('/'))}
+}
+
+// Insert 插入一个关键字
+func (trie *Trie) Insert(key string) {
+	node := trie.root
+	for _, v := range key { // 注：for range采用Unicode字符遍历
+		child, ok := node.children[v]
+		if !ok {
+			child = NewTrieNode(v)
+			node.children[v] = child
+		}
+		node = child
+	}
+	node.isEnd = true
+}
+
+// Find 查找关键字，存在返回true，否则返回false
+func (trie *Trie) Find(key string) bool {
+	node := trie.root
+	for _, v := range key {
+		child, ok := node.children[v]
+		if !ok {
+			return false
+		}
+		node = child
+	}
+	return node.isEnd
+}

tree/Trie/trie_test.go

@@ -0,0 +1,35 @@
+package trie
+
+import (
+	"testing"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTrie(t *testing.T) {
+	keys := []string{
+		"hi",
+		"hello",
+		"world",
+		"height",
+		"he",
+		"him",
+		"Hi",
+		"中国",
+		"成都",
+		"北京欢迎您",
+	}
+
+	trie := NewTrie()
+	for _, key := range keys {
+		trie.Insert(key)
+	}
+
+	assert.Equal(t, true, trie.Find("hi"))
+	assert.Equal(t, true, trie.Find("中国"))
+	assert.Equal(t, false, trie.Find("h"))
+	assert.Equal(t, false, trie.Find("北京"))
+	assert.Equal(t, false, trie.Find("heigh"))
+
+	
+
+}