[백준 알고리즘] 숨박꼭질(1697 - BFS - 자바)

 

 

 

 

package jae.pro.backjoon;
 
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
 
public class HideSeek {
 
    static int min = Integer.MAX_VALUE;
    static int bro;
    static int su2;
    static boolean visited[] = new boolean[100001];
 
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
 
        su2 = sc.nextInt();
        bro = sc.nextInt();
 
        bfs(su2, bro);
    }
    //범위 체크
    public static boolean isRange(int x) {
        if (x >= 0 && x <= 100000)
            return true;
        return false;
    }
 
    public static void bfs(int su, int bro) {
        Queue<pair> queue = new LinkedList<>();
 
        visited[su] = true;
        queue.offer(new pair(su, 0));
 
        while (!queue.isEmpty()) {
            pair p = queue.poll();
            //위치
            int a = p.y;
            //시간
            int b = p.x;
 
            if (a == bro) {
                System.out.println(b);
                break;
            }
 
            if (isRange(a * 2) && !visited[a * 2]) {
                queue.offer(new pair(a * 2, b + 1));
                visited[a * 2] = true;
            }
            if (isRange(a + 1) && !visited[a + 1]) {
                queue.offer(new pair(a + 1, b + 1));
                visited[a + 1] = true;
            }
            if (isRange(a - 1) && !visited[a - 1]) {
                queue.offer(new pair(a - 1, b + 1));
                visited[a - 1] = true;
            }
 
        }
 
    }
 
    static class pair {
        int y;
        int x;
 
        public pair(int y, int x) {
            this.y = y;
            this.x = x;
        }
 
    }
 
}