[백준 - 1316] 그룹 단어 체커

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
 
        int test = scanner.nextInt();
 
        String[] list = new String[test];
        for(int i = 0; i < test; ++i) {
            String s = scanner.next();
            list[i] = s;
        }
 
        int cnt = 0;
        for(String s : list){
            boolean check = check(s);
            if(check){
                cnt++;
            }
        }
        System.out.println(cnt);
    }
    public static boolean check(String s){
 
        HashMap<Character, ArrayList<Integer>> map = new HashMap<>();
 
        for(int i = 0; i < s.length(); ++i){
            char a = s.charAt(i);
            if(map.get(a) != null){
                ArrayList<Integer> list = map.get(a);
                list.add(i);
                map.put(a,list);
            }else{
                ArrayList<Integer> list = new ArrayList<>();
                list.add(i);
                map.put(a, list);
            }
        }
 
        Iterator it = map.keySet().iterator();
        while(it.hasNext()){
            ArrayList<Integer> list = map.get(it.next());
            for(int i = 0; i < list.size(); ++i){
                if(i > 0){
                    if(list.get(i) - list.get(i-1) >1){
                        return false;
                    }
                }
            }
        }
        return true;
    }
}

 

출처 : www.acmicpc.net/problem/1316