规范格式

leetcode/0208.Implement-Trie-Prefix-Tree/208. Implement Trie (Prefix Tree).go

@@ -0,0 +1,60 @@
+package leetcode
+
+type Trie struct {
+	isWord   bool
+	children map[rune]*Trie
+}
+
+/** Initialize your data structure here. */
+func Constructor208() Trie {
+	return Trie{isWord: false, children: make(map[rune]*Trie)}
+}
+
+/** Inserts a word into the trie. */
+func (this *Trie) Insert(word string) {
+	parent := this
+	for _, ch := range word {
+		if child, ok := parent.children[ch]; ok {
+			parent = child
+		} else {
+			newChild := &Trie{children: make(map[rune]*Trie)}
+			parent.children[ch] = newChild
+			parent = newChild
+		}
+	}
+	parent.isWord = true
+}
+
+/** Returns if the word is in the trie. */
+func (this *Trie) Search(word string) bool {
+	parent := this
+	for _, ch := range word {
+		if child, ok := parent.children[ch]; ok {
+			parent = child
+			continue
+		}
+		return false
+	}
+	return parent.isWord
+}
+
+/** Returns if there is any word in the trie that starts with the given prefix. */
+func (this *Trie) StartsWith(prefix string) bool {
+	parent := this
+	for _, ch := range prefix {
+		if child, ok := parent.children[ch]; ok {
+			parent = child
+			continue
+		}
+		return false
+	}
+	return true
+}
+
+/**
+ * Your Trie object will be instantiated and called as such:
+ * obj := Constructor();
+ * obj.Insert(word);
+ * param_2 := obj.Search(word);
+ * param_3 := obj.StartsWith(prefix);
+ */

leetcode/0208.Implement-Trie-Prefix-Tree/208. Implement Trie (Prefix Tree)_test.go

@@ -0,0 +1,23 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+func Test_Problem208(t *testing.T) {
+	obj := Constructor208()
+	fmt.Printf("obj = %v\n", obj)
+	obj.Insert("apple")
+	fmt.Printf("obj = %v\n", obj)
+	param1 := obj.Search("apple")
+	fmt.Printf("param_1 = %v obj = %v\n", param1, obj)
+	param2 := obj.Search("app")
+	fmt.Printf("param_2 = %v obj = %v\n", param2, obj)
+	param3 := obj.StartsWith("app")
+	fmt.Printf("param_3 = %v obj = %v\n", param3, obj)
+	obj.Insert("app")
+	fmt.Printf("obj = %v\n", obj)
+	param4 := obj.Search("app")
+	fmt.Printf("param_4 = %v obj = %v\n", param4, obj)
+}

leetcode/0208.Implement-Trie-Prefix-Tree/README.md

@@ -0,0 +1,31 @@
+# [208. Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/)
+
+
+## 题目
+
+Implement a trie with `insert`, `search`, and `startsWith` methods.
+
+**Example:**
+
+    Trie trie = new Trie();
+    
+    trie.insert("apple");
+    trie.search("apple");   // returns true
+    trie.search("app");     // returns false
+    trie.startsWith("app"); // returns true
+    trie.insert("app");   
+    trie.search("app");     // returns true
+
+**Note:**
+
+- You may assume that all inputs are consist of lowercase letters `a-z`.
+- All inputs are guaranteed to be non-empty strings.
+
+## 题目大意
+
+实现一个 Trie (前缀树)，包含 insert, search, 和 startsWith 这三个操作。
+
+## 解题思路
+
+- 要求实现一个 Trie 的数据结构，具有 `insert`, `search`, `startsWith` 三种操作
+- 这一题就是经典的 Trie 实现。本题的实现可以作为 Trie 的模板。