[BOJ] 14503 로봇 청소기

[문제]

https://www.acmicpc.net/problem/14503

 

 

[소스 코드]

import java.io.*;
import java.util.*;

public class Main {
	static int[] dr = {-1,0,1,0};
	static int[] dc = {0,1,0,-1};
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		int n = Integer.parseInt(st.nextToken());
		int m = Integer.parseInt(st.nextToken());
		st = new StringTokenizer(br.readLine());
		int r = Integer.parseInt(st.nextToken());
		int c = Integer.parseInt(st.nextToken());
		int dir = Integer.parseInt(st.nextToken());
		int[][] map = new int[n][m];
		for(int i=0;i<n;i++) {
			st = new StringTokenizer(br.readLine());
			for(int j=0;j<m;j++) {
				map[i][j] = Integer.parseInt(st.nextToken());
			}
		}
		int result = 0;
		out:
		while(true) {
			if(map[r][c]==0) {
				map[r][c] = 2;
				result++;
			}
			int cnt = 0;
			for(int d=0;d<4;d++) {
				int nr = r + dr[d];
				int nc = c + dc[d];
				if(nr<0 || nr>=n || nc<0 || nc>=m || map[nr][nc]==1) continue;
				if(map[nr][nc]==0) cnt++;
			}
			if(cnt==0) {
				int nr = r + dr[(dir+2)%4];
				int nc = c + dc[(dir+2)%4];
				if(nr<0 || nr>=n || nc<0 || nc>=m || map[nr][nc]==1) break out;
				r = nr; c = nc;
			}
			else {
				for(int d=0;d<4;d++) {
					dir = (dir+3) % 4;
					int nr = r + dr[dir];
					int nc = c + dc[dir];
					if(nr<0 || nr>=n || nc<0 || nc>=m || map[nr][nc]==1) continue;
					if(map[nr][nc]==0) {
						r = nr; c = nc;
						break;
					}
				}
			}
		}
		System.out.println(result);
	}
}