토끼가 정보섬에 올라온 이유

pr/토끼가 정보섬에 올라온 이유/Main.java

@@ -0,0 +1,106 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) {
+        new Main().run();
+    }
+    public void run() {
+        FastReader fr = new FastReader();
+                int n = Integer.parseInt(fr.next());
+        int m = Integer.parseInt(fr.next());
+        char[][] grid = new char[n][];
+        for(int i=0; i<n; i++) grid[i] = fr.next().toCharArray();
+        this.n = n;
+        this.m = m;
+        this.grid = grid;
+        System.out.println(this.solve(n, m, grid));
+    }
+    public int n;
+    public int m;
+    public char[][] grid;
+
+    public int[] dx = { -1, 0, 1 };
+    public int[] dy = { 1, 1, 1 };
+
+    public int[][] memo;
+
+    /**
+     * 문제 해결 메서드
+     * 
+     * @param n    행의 수
+     * @param m    열의 수
+     * @param grid 격자 데이터
+     * @return 문제에 맞는 반환 타입
+     */
+    public int solve(int n, int m, char[][] grid) {
+        this.n = n;
+        this.m = m;
+        this.grid = grid;
+        this.memo = new int[n][m];
+        for (int i = 0; i < n; i++) {
+            Arrays.fill(memo[i], -1);
+        }
+
+        int rx = -1;
+        int ry = -1;
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < m; j++) {
+                if (grid[i][j] == 'R') {
+                    rx = i;
+                    ry = j;
+                }
+            }
+        }
+
+        return dfs(rx, ry) <= -987654321 ? -1 : dfs(rx, ry);
+    }
+
+    public int dfs(int x, int y) {
+        int res = -987654321;
+
+        if (grid[x][y] == 'O') {
+            res = 0;
+        }
+        if (memo[x][y] != -1) {
+            return memo[x][y];
+        }
+
+        for (int i = 0; i < 3; i++) {
+            int cc = 0;
+
+            int nx = dx[i] + x;
+            int ny = dy[i] + y;
+
+            if (nx < 0 || n <= nx)
+                continue;
+            if (ny < 0 || m <= ny)
+                continue;
+            if (grid[nx][ny] == '#') {
+                continue;
+            }
+
+            if (grid[nx][ny] == 'C') {
+                cc++;
+            }
+
+            int next = dfs(nx, ny);
+
+            if (next != -987654321) {
+                res = Math.max(res, cc + next);
+            }
+        }
+
+        return memo[x][y] = res;
+
+    }
+
+    static class FastReader {
+        BufferedReader br; StringTokenizer st;
+        public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); }
+        public String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { } } return st.nextToken(); }
+        public int nextInt() { return Integer.parseInt(next()); }
+        public long nextLong() { return Long.parseLong(next()); }
+        public boolean hasMoreTokens() { while (st == null || !st.hasMoreElements()) { String line = null; try { line = br.readLine(); } catch (IOException e) { } if (line == null) return false; st = new StringTokenizer(line); } return true; }
+    }
+}