[20250305] BOJ / G2 / 모래성 / 권혁준

Author: oncsr

khj20006/202503/05 BOJ G2 모래성.md

@@ -0,0 +1,82 @@
+```java
+
+import java.util.*;
+import java.io.*;
+
+class Main {
+	
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st;
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static int nextInt() {return Integer.parseInt(st.nextToken());}
+	static long nextLong() {return Long.parseLong(st.nextToken());}
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+	
+	// Additional field
+
+	static int H, W;
+	static int[][] A;
+	static boolean[][] vis;
+	static int[] dx = {1,1,1,0,0,-1,-1,-1};
+	static int[] dy = {1,0,-1,1,-1,1,0,-1};
+	
+	public static void main(String[] args) throws Exception {
+		
+		ready();
+		solve();
+	
+		bwEnd();
+		
+	}
+	
+	static void ready() throws Exception{
+		
+		nextLine();
+		H = nextInt();
+		W = nextInt();
+		A = new int[H][W];
+		vis = new boolean[H][W];
+		for(int i=0;i<H;i++) {
+			char[] temp = br.readLine().toCharArray();
+			for(int j=0;j<W;j++) {
+				if(temp[j] == '.') continue;
+				A[i][j] = temp[j]-'0';
+			}
+		}
+		
+	}
+	
+	static void solve() throws Exception{
+		
+		int ans = 0;
+		
+		Queue<int[]> Q = new LinkedList<>();
+		for(int i=0;i<H;i++) for(int j=0;j<W;j++) if(A[i][j] == 0) {
+			vis[i][j] = true;
+			Q.add(new int[] {i,j,0});
+		}
+		
+		while(!Q.isEmpty()) {
+			int[] now = Q.poll();
+			int x = now[0], y = now[1], time = now[2];
+			ans = time;
+			for(int k=0;k<8;k++) {
+				int xx = x+dx[k], yy = y+dy[k];
+				if(xx<0 || xx>=H || yy<0 || yy>=W || vis[xx][yy]) continue;
+				if(--A[xx][yy] == 0) {
+					vis[xx][yy] = true;
+					Q.add(new int[] {xx,yy,time+1});
+				}
+			}
+		}
+		
+		bw.write(ans + "\n");
+		
+	}
+	
+}
+
+```