[BFS] baekjoon-2206

Author: Seogeurim

Diff for: README.md

@@ -136,6 +136,7 @@
 | 15  |     | [SWEA-1953 탈주범 검거](./src/BFS/swea1953)        |                          |
 | 16  |     | [SWEA-10966 물놀이를 가자](./src/BFS/swea10966)     |                          |
 | 17  |     | [SWEA-1238 Contact](./src/BFS/swea1238)          |                          |
+| 18  |     | [Baekjoon-2206 벽 부수고 이동하기](./src/BFS/P2206)  |                          |
 
 ## Divide and Conquer
 

Diff for: src/BFS/P2206/Main.java

@@ -0,0 +1,71 @@
+package BFS.P2206;
+
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N, M;
+    static char[][] map;
+    static int[] di = {-1, 0, 1, 0};
+    static int[] dj = {0, 1, 0, -1};
+
+    public static void main(String[] args) throws Exception {
+        System.setIn(new FileInputStream("src/BFS/P2206/input.txt"));
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        map = new char[N][M];
+        for (int i = 0; i < N; i++) {
+            map[i] = br.readLine().toCharArray();
+        }
+
+        System.out.println(bfs());
+    }
+
+    static int bfs() {
+        Queue<Pos> q = new LinkedList<>();
+        boolean[][][] visited = new boolean[N][M][2];
+
+        q.offer(new Pos(0, 0, 1, 1));
+        visited[0][0][1] = true;
+        while (!q.isEmpty()) {
+            Pos p = q.poll();
+            if (p.i == N-1 && p.j == M-1) return p.dist;
+
+            for (int k = 0; k < 4; k++) {
+                int to_i = p.i + di[k];
+                int to_j = p.j + dj[k];
+
+                if (!isValidPath(to_i, to_j)) continue;
+                if (map[to_i][to_j] == '0' && !visited[to_i][to_j][p.wall]) {
+                    visited[to_i][to_j][p.wall] = true;
+                    q.offer(new Pos(to_i, to_j, p.dist+1, p.wall));
+                } else if (p.wall > 0) {
+                    visited[to_i][to_j][0] = true;
+                    q.offer(new Pos(to_i, to_j, p.dist+1, p.wall-1));
+                }
+            }
+        }
+
+        return -1;
+    }
+
+    static boolean isValidPath(int i, int j) {
+        return 0 <= i && i < N && 0 <= j && j < M;
+    }
+
+    static class Pos {
+        int i, j, dist, wall;
+
+        public Pos(int i, int j, int dist, int wall) {
+            this.i = i;
+            this.j = j;
+            this.dist = dist;
+            this.wall = wall;
+        }
+    }
+}

Diff for: src/BFS/P2206/README.md

@@ -0,0 +1,5 @@
+## [baekjoon-2206] 벽 부수고 이동하기
+
+![image](https://user-images.githubusercontent.com/22045163/112110431-3a399500-8bf6-11eb-816c-413bd9e74978.png)
+
+![image](https://user-images.githubusercontent.com/22045163/112110467-44f42a00-8bf6-11eb-9a9a-d189d0873534.png)

Diff for: src/BFS/P2206/input.txt

@@ -0,0 +1,7 @@
+6 4
+0100
+1110
+1000
+0000
+0111
+0000