13549. 숨바꼭질3 (Java)

단순 BFS 문제였다. *2를 할때는 cnt를 증가시키지않고 푸는것이 핵심

package Boj;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;
import java.util.StringTokenizer;

public class Main {    
 
    static int min = Integer.MAX_VALUE;
    static int n, k;
    static boolean[] visited;
    static int max = 100000;
    
    public static class Node {
        int x;
        int time;
        
        public Node(int x, int time) {
            this.x = x;
            this.time = time;
        }
    }

    public static void bfs() {
        Queue<Node> q = new LinkedList<>();
        q.offer(new Node(n, 0));
        
        while(!q.isEmpty()) {
            Node node = q.poll();
            visited[node.x] = true;
            if(node.x == k) min = Math.min(min, node.time);
            
            if(node.x * 2 <= max && visited[node.x * 2] == false) q.offer(new Node(node.x * 2, node.time));
            if(node.x + 1 <= max && visited[node.x + 1] == false) q.offer(new Node(node.x + 1, node.time + 1));
            if(node.x - 1 >= 0 && visited[node.x - 1] == false) q.offer(new Node(node.x - 1, node.time + 1));
        }
    }

    public static void main(String args[]) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        n = Integer.parseInt(st.nextToken());
        k = Integer.parseInt(st.nextToken());
        
        visited = new boolean[max + 1];
        bfs();
        System.out.println(min);
    } 
}