[프로그래머스] 자동완성 (2018 KAKAO BLIND RECRUITMENT)

programmers.co.kr/learn/courses/30/lessons/17685

코딩테스트 연습 - [3차] 자동완성

2021-03-01

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public class Solution17685 {
    static class TrieNode {
        TrieNode[] next;
        int count = 0;
 
        TrieNode() {
            next = new TrieNode[26];
            this.count = 0;
        }
    }
 
    static class Trie {
        TrieNode root;
 
        Trie() {
            root = new TrieNode();
        }
 
        void insert(String str) {
            TrieNode node = root;
 
            for(int i = 0; i < str.length(); i++) {
                int idx = str.charAt(i) - 'a';
                if(node.next[idx] == null) node.next[idx] = new TrieNode();
                node.next[idx].count++;
                node = node.next[idx];
            }
        }
 
        int count(String str) {
            TrieNode node = root;
            int cnt = 0;
            for(int i = 0; i < str.length(); i++) {
                int idx = str.charAt(i) - 'a';
                cnt++;
                if(node.next[idx].count == 1) return cnt;
                node = node.next[idx];
            }
            return cnt;
        }
    }
 
    public static int solution(String[] words) {
        int answer = 0;
        Trie t = new Trie();
        for (String word : words) {
            t.insert(word);
        }
 
        for(String word: words) {
            answer += t.count(word);
        }
        return answer;
    }
 
    public static void main(String[] args) {
        String[] w = {"go", "gone", "guild"};
//        String[] w = {"abc","def","ghi","jklm"};
        System.out.println(solution(w));
 
    }
}