백준 14503. 로봇 청소기 문제풀이 자바 JAVA

1private static class Info {
2    private final int x;
3    private final int y;
4    public Info(int x, int y) {
5        this.x = x;
6        this.y = y;
7    }
8
9    public int getX() {
10        return x;
11    }
12    public int getY() {
13        return y;
14    }
15}

1private static int validateValue(Info info) {
2    int x = info.getX();
3    int y = info.getY();
4
5    if (y > 0 && y < M - 1 && x > 0 && x < N - 1) {
6        if (map[x][y] != 1) {
7            return map[x][y];
8        }
9    }
10    return -1;
11}

1private static boolean setCheck(Info info) {
2    int x = info.getX();
3    int y = info.getY();
4
5    if (map[x][y] == 0) {
6        map[x][y] = 2;
7        return true;
8    }
9    return false;
10}

1static int[] moveX = {-1, 0, 1, 0};
2static int[] moveY = {0, 1, 0, -1};

1private static void turn() {
2    if (--d == -1) d = 3;
3}

1private static int back() {
2    if (d <= 1) return d + 2;
3    return d - 2;
4}

1BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
2
3StringTokenizer st = new StringTokenizer(br.readLine(), " ");
4
5N = Integer.parseInt(st.nextToken());
6M = Integer.parseInt(st.nextToken());
7
8map = new int[N][M];
9
10st = new StringTokenizer(br.readLine(), " ");
11
12r = Integer.parseInt(st.nextToken());
13c = Integer.parseInt(st.nextToken());
14d = Integer.parseInt(st.nextToken());
15
16for (int i = 0; i < N; i++) {
17    st = new StringTokenizer(br.readLine(), " ");
18    for (int j = 0; j < M; j++) {
19        map[i][j] = Integer.parseInt(st.nextToken());
20    }
21}

1package BOJ;
2
3import java.io.BufferedReader;
4import java.io.IOException;
5import java.io.InputStreamReader;
6import java.util.StringTokenizer;
7
8public class Boj_14503 {
9	static int N, M, r, c, d;
10	static int[][] map;
11	static int[] moveX = {-1, 0, 1, 0};
12	static int[] moveY = {0, 1, 0, -1};
13	static int result = 0;
14
15	public static void main(String[] args) throws IOException {
16		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
17
18		StringTokenizer st = new StringTokenizer(br.readLine(), " ");
19
20		N = Integer.parseInt(st.nextToken());
21		M = Integer.parseInt(st.nextToken());
22
23		map = new int[N][M];
24
25		st = new StringTokenizer(br.readLine(), " ");
26
27		r = Integer.parseInt(st.nextToken());
28		c = Integer.parseInt(st.nextToken());
29		d = Integer.parseInt(st.nextToken());
30
31		for (int i = 0; i < N; i++) {
32			st = new StringTokenizer(br.readLine(), " ");
33			for (int j = 0; j < M; j++) {
34				map[i][j] = Integer.parseInt(st.nextToken());
35			}
36		}
37		DFS(new Info(r, c));
38		System.out.println(result);
39	}
40
41	static private void DFS(Info currentInfo) {
42		// x, y좌표의 값을 1로 변경. 청소가 되지 않은 상태였다면 청소를 한 칸이므로 result++
43		if (setCheck(currentInfo)) {
44			result++;
45		}
46
47		boolean flag = false;
48		for (int i = 0; i < 4; i++) {
49			Info nextValue = new Info(currentInfo.getX() + moveX[i], currentInfo.getY() + moveY[i]);
50
51			// 청소되지 않은 구역이 하나라도 있는 경우 flag = true
52			if (validateValue(nextValue) == 0) {
53				flag = true;
54				break;
55			}
56		}
57
58		// 주변에 빈 청소 구역이 있는 경우. 반시계 방향으로 회전 후 빈칸인 경우 한칸 전진 후 DFS.
59		if (flag) {
60			turn();
61			Info nextValue = new Info(currentInfo.getX() + moveX[d], currentInfo.getY() + moveY[d]);
62
63			if (validateValue(nextValue) == 0) {
64				DFS(nextValue);
65			} else {
66				// 빈칸이 아니라면 다시 재귀
67				DFS(currentInfo);
68			}
69		} else {
70			// 빈 청소 구역이 없는 경우, 후진하고 DFS.
71			int backDirection = back();
72			Info nextValue = new Info(currentInfo.getX() + moveX[backDirection], currentInfo.getY() + moveY[backDirection]);
73
74			if (validateValue(nextValue) != -1) {
75				DFS(nextValue);
76			}
77		}
78	}
79
80	private static class Info {
81		private final int x;
82		private final int y;
83
84		public Info(int x, int y) {
85			this.x = x;
86			this.y = y;
87		}
88
89		public int getX() {
90			return x;
91		}
92		public int getY() {
93			return y;
94		}
95	}
96
97	private static int validateValue(Info info) {
98		int x = info.getX();
99		int y = info.getY();
100
101		if (y > 0 && y < M - 1 && x > 0 && x < N - 1) {
102			if (map[x][y] != 1) {
103				return map[x][y];
104			}
105		}
106		return -1;
107	}
108
109	private static boolean setCheck(Info info) {
110		int x = info.getX();
111		int y = info.getY();
112
113		if (map[x][y] == 0) {
114			map[x][y] = 2;
115			return true;
116		}
117		return false;
118	}
119
120	private static void turn() {
121		if (--d == -1) d = 3;
122	}
123
124	private static int back() {
125		if (d <= 1) return d + 2;
126		return d - 2;
127	}
128}