package top100liked

import (
	"fmt"
	"testing"
)

// https://leetcode.cn/problems/implement-trie-prefix-tree/?envType=study-plan-v2&envId=top-100-liked

type Node struct {
	children [26]*Node
	isEnd    bool
}

type Trie struct {
	root *Node
}

func Constructor() Trie {
	return Trie{root: &Node{}}
}

func (this *Trie) Insert(word string) {
	cur := this.root
	for i := 0; i < len(word); i++ {
		idx := word[i] - 'a'
		if cur.children[idx] == nil {
			cur.children[idx] = &Node{}
		}
		cur = cur.children[idx]
	}
	cur.isEnd = true
}

func (this *Trie) Search(word string) bool {
	cur := this.root
	for i := 0; i < len(word); i++ {
		idx := word[i] - 'a'
		if cur.children[idx] == nil {
			return false
		}
		cur = cur.children[idx]
	}
	return cur.isEnd
}

func (this *Trie) StartsWith(prefix string) bool {
	cur := this.root
	for i := 0; i < len(prefix); i++ {
		idx := prefix[i] - 'a'
		if cur.children[idx] == nil {
			return false
		}
		cur = cur.children[idx]
	}
	return true
}

func Test(t *testing.T) {
	trie := Constructor()
	trie.Insert("apple")
	fmt.Println(trie.Search("apple"))   // 返回 True
	fmt.Println(trie.Search("app"))     // 返回 False
	fmt.Println(trie.StartsWith("app")) // 返回 True
	trie.Insert("app")
	fmt.Println(trie.Search("app")) // 返回 True
}