[20250314] BOJ / G3 / 피리 부는 사나이 / 김수연

suyeun84/202503/14 BOJ G3 피리 부는 사나이.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class boj16724 {
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+	static boolean[][] visited, finished;
+	static int answer;
+	static int[][] board;
+	static int[] dr = {-1,1,0,0};
+	static int[] dc = {0,0,-1,1};
+	public static void main(String[] args) throws Exception{
+		StringTokenizer st = new StringTokenizer(br.readLine());
+
+		int N = Integer.parseInt(st.nextToken());
+		int M = Integer.parseInt(st.nextToken());
+
+		board = new int[N][M];
+		visited = new boolean[N][M];
+		finished = new boolean[N][M];
+		answer = 0;
+
+		for(int i=0;i<N;i++) {
+			String line = br.readLine();
+			for(int j=0;j<M;j++) {
+				int c = line.charAt(j);
+				if(c == 'U') board[i][j] = 0;
+				else if(c == 'D') board[i][j] = 1;
+				else if(c == 'L') board[i][j] = 2;
+				else if(c == 'R') board[i][j] = 3;
+			}
+		}
+
+		for(int i=0;i<N;i++) {
+			for(int j=0;j<M;j++) {
+				if(!visited[i][j]) dfs(i,j);
+			}
+		}
+		System.out.println(answer);
+	}
+
+	public static void dfs(int r, int c) {
+
+		visited[r][c] = true;
+
+		int nr = r + dr[board[r][c]];
+		int nc = c + dc[board[r][c]];
+
+		if(!visited[nr][nc]) {
+			dfs(nr,nc);
+		}else {
+			if(!finished[nr][nc]) answer++;
+		}
+		finished[r][c] = true;
+	}
+}
+
+```