Merge pull request #1861 from AlgorithmWithGod/LiiNi-coder

[20260130] BOJ / G5 / 로봇 청소기 / 이인희

Author: ShinHeeEul

LiiNi-coder/202601/30 BOJ 로봇 청소기.md

@@ -0,0 +1,99 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+public class Main{
+	private static int N, M;
+	private static int Vd; // 0북 1동 2남
+	private static char[][] Map;
+	private static int Vr, Vc;
+	private static final int[][] Drdcs = {
+		{-1, 0},
+		{0, 1},
+		{1, 0},
+		{0, -1}
+	};
+	public static void main(String[] args) throws IOException {
+		/*
+		로봇청소기 N*M
+		(0, 0) 시작
+		N, M <= 50,
+		d = 0북 1동 2남
+		작동 멈출때까지 청소하는 칸 개수
+		 */
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		String[] tokens = br.readLine().split(" ");
+		N = Integer.parseInt(tokens[0]);
+		M = Integer.parseInt(tokens[1]);
+		Map = new char[N+2][M+2];
+		tokens = br.readLine().split(" ");
+		Vr = Integer.parseInt(tokens[0]) + 1;
+		Vc = Integer.parseInt(tokens[1]) + 1;
+		Vd = Integer.parseInt(tokens[2]);
+		for(int c = 0; c<M+2; c++){
+			for(int r : new int[]{0, N+1}){
+				Map[r][c] = 'W';
+			}
+		}
+		for(int r=1; r<N+1; r++){
+			for(int c: new int[]{0, M+1}){
+				Map[r][c] = 'W';
+			}
+		}
+		for(int r = 1; r<N+1; r++){
+			tokens = br.readLine().split(" ");
+			for(int c = 1; c<M+1; c++){
+				int isWall = Integer.parseInt(tokens[c-1]);
+				if(isWall == 1){
+					Map[r][c] = 'W';
+				}else{
+					Map[r][c] = 'X';
+				}
+			}
+		}
+		int answer = 0;
+		while(true) {
+			//1. 현재칸 청소X->현재칸 청소
+			if(Map[Vr][Vc] == 'X'){
+				Map[Vr][Vc] = 'O';
+				answer++;
+			}
+			//2. 현재칸 주변4칸에 청소되지않은 빈칸이없을때
+			boolean isNotX = true;
+			for(int i = -1; i>= -4; i--){
+				int nd = addDirenction(Vd, i);
+				int nr = Vr + Drdcs[nd][0];
+				int nc = Vc + Drdcs[nd][1];
+				if(Map[nr][nc] == 'X'){
+					Vd = nd;
+					Vr = nr;
+					Vc = nc;
+					isNotX = false;
+					break;
+				}
+			}
+			if(isNotX){
+				int nr = Vr + Drdcs[addDirenction(Vd, 2)][0];
+				int nc = Vc + Drdcs[addDirenction(Vd, 2)][1];
+				if(Map[nr][nc] != 'W'){
+					Vr = nr; Vc = nc;
+					continue;
+				}else{
+					break;
+				}
+			}
+			// 2-1.후진가능-> 한칸 후진 후 1로
+			// 2-2.후진불가능->작동멈춤
+			//3. 현재칸 주변 4칸 중 청소된지않은 빈칸 존재
+			// 3-1. 반시계90도회전
+			// 3-2.현 방향 앞이 청소되지않았으면 한칸 전진
+		}
+		System.out.println(answer);
+		br.close();
+	}
+	private static int addDirenction(int vd, int i){
+		return (vd + Drdcs.length) % Drdcs.length;
+	}
+
+}
+```