add: tire tree

test/basic/alogrithm/tire_test.go

@@ -0,0 +1,119 @@
+package alogrithm
+
+import (
+	"testing"
+)
+
+func TestTrieIsPrefixMatch(t *testing.T) {
+	trie := NewTrie()
+
+	prefixes := []string{"apple", "app", "ball", "c", "ccc"}
+	for _, p := range prefixes {
+		trie.Insert(p)
+	}
+
+	checkWords := map[string]bool{
+		"a":     false,
+		"ap":    false,
+		"app":   true,
+		"appl":  true,
+		"appla": true,
+		"apx":   false,
+		"ban":   false,
+		"bal":   false,
+		"ball":  true,
+		"c":     true,
+		"cc":    true,
+	}
+	for word, expected := range checkWords {
+		if trie.IsPrefixMatch(word) != expected {
+			t.Fatalf("%s : expected(%v), actual(%v)", word, expected, trie.IsPrefixMatch(word))
+		}
+	}
+}
+
+func TestTrieSearch(t *testing.T) {
+	trie := NewTrie()
+
+	keyWords := []string{"apple", "app", "ball", "c", "ccc"}
+	for _, p := range keyWords {
+		trie.Insert(p)
+	}
+
+	checkWords := map[string]bool{
+		"a":     false,
+		"ap":    false,
+		"app":   true,
+		"appl":  false,
+		"appla": false,
+		"apx":   false,
+		"ban":   false,
+		"bal":   false,
+		"ball":  true,
+		"c":     true,
+		"cc":    false,
+	}
+	for word, expected := range checkWords {
+		if trie.Search(word) != expected {
+			t.Fatalf("%s : expected(%v), actual(%v)", word, expected, trie.Search(word))
+		}
+	}
+}
+
+type TrieNode struct {
+	children map[rune]*TrieNode
+	isEnd    bool
+}
+
+// Trie, not concurrency safe
+type Trie struct {
+	root *TrieNode
+}
+
+func NewTrie() *Trie {
+	return &Trie{
+		root: &TrieNode{
+			children: make(map[rune]*TrieNode),
+			isEnd:    false,
+		},
+	}
+}
+
+func (t *Trie) Insert(word string) {
+	node := t.root
+	for _, ch := range word {
+		if node.children[ch] == nil {
+			node.children[ch] = &TrieNode{
+				children: make(map[rune]*TrieNode),
+				isEnd:    false,
+			}
+		}
+		node = node.children[ch]
+	}
+	node.isEnd = true
+}
+
+func (t *Trie) IsPrefixMatch(word string) bool {
+	node := t.root
+	for _, ch := range word {
+		node = node.children[ch]
+		if node == nil {
+			return false
+		}
+		if node.isEnd {
+			return true
+		}
+	}
+	return false
+}
+
+func (t *Trie) Search(word string) bool {
+	node := t.root
+	for _, ch := range word {
+		node = node.children[ch]
+		if node == nil {
+			return false
+		}
+	}
+	return node.isEnd
+}