백준 1697번 숨바꼭질 [ Java ]

 

1697번: 숨바꼭질

처음에 N==K인 반례를 놓쳤었습니다.

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList<Integer> Q = new ArrayList<>();
        int N = sc.nextInt();
        int K = sc.nextInt();
        if (N==K){
            System.out.print(0);
            System.exit(0);
        }
        int[] dist = new int[100001];
        Arrays.fill(dist, -1);
        dist[N] = 0;
        Q.add(N);
        while(!Q.isEmpty()){
            int cur = Q.remove(0);
            for (int dir : new int[]{cur-1, cur+1, cur*2}){
                if (dir == K){
                    System.out.print(dist[cur]+1);
                    System.exit(0);
                }
                if (dir<0 || dir>=dist.length) continue;
                if (dist[dir]>=0) continue;
                dist[dir] = dist[cur]+1;
                Q.add(dir);
            }
        }
    }
}