[20251023] BOJ / G1 / 수영장 만들기 / 김수연

suyeun84/202510/23 BOJ G1 수영장 만들기.md

@@ -0,0 +1,70 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class boj1113 {
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static StringTokenizer st;
+    static void nextLine() throws Exception { st = new StringTokenizer(br.readLine()); }
+    static int nextInt() { return Integer.parseInt(st.nextToken()); }
+
+    static int[][] dir = new int[][] {{1,0}, {-1,0}, {0,1}, {0,-1}};
+    static int N, M, answer;
+    static int[][] land;
+    static boolean[][] visited;
+    static Queue<int[]> q = new LinkedList<>();
+    public static void main(String[] args) throws Exception {
+        nextLine();
+        N = nextInt();
+        M = nextInt();
+        int min = Integer.MAX_VALUE;
+        int max = Integer.MIN_VALUE;
+        answer = 0;
+        land = new int[N][M];
+        visited = new boolean[N][M];
+        for (int i = 0; i < N; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < M; j++) {
+                land[i][j] = Integer.parseInt(line.substring(j, j+1));
+                min = Math.min(min, land[i][j]);
+                max = Math.max(max, land[i][j]);
+            }
+        }
+        for (int h = min; h < max; h++) {
+            for (int i = 1; i < N-1; i++) {
+                for (int j = 1; j < M-1; j++) {
+                    if (land[i][j] == h) {
+                        answer += bfs(i, j, h);
+                    }
+                }
+            }
+        }
+        System.out.println(answer);
+    }
+
+    static int bfs(int y, int x, int h) {
+        q.clear();
+        q.add(new int[] {y, x});
+        int cnt = 1;
+        boolean flag = true;
+        land[y][x] = h + 1;
+        while (!q.isEmpty()) {
+            int[] cur = q.poll();
+            for (int[] d : dir) {
+                int ny = cur[0] + d[0];
+                int nx = cur[1] + d[1];
+                if (ny < 0 || ny >= N || nx < 0 || nx >= M || land[ny][nx] < h) {
+                    flag = false;
+                    continue;
+                }
+                if (h != land[ny][nx]) continue;
+                land[ny][nx] = h + 1;
+                cnt++;
+                q.offer(new int[] {ny, nx});
+            }
+        }
+        if (flag) return cnt;
+        return 0;
+    }
+}
+```