From e97b437e2b10e64dfce205a8266612267ee18520 Mon Sep 17 00:00:00 2001
From: suyeun84 <81475092+suyeun84@users.noreply.github.com>
Date: Thu, 18 Sep 2025 23:29:12 +0900
Subject: [PATCH] =?UTF-8?q?[20250918]=20PGM=20/=20LV2=20/=20=EC=A7=80?=
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---
 ...0 \355\201\254\353\240\210\354\235\270.md" | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 "suyeun84/202509/18 PGM LV2 \354\247\200\352\262\214\354\260\250\354\231\200 \355\201\254\353\240\210\354\235\270.md"

diff --git "a/suyeun84/202509/18 PGM LV2 \354\247\200\352\262\214\354\260\250\354\231\200 \355\201\254\353\240\210\354\235\270.md" "b/suyeun84/202509/18 PGM LV2 \354\247\200\352\262\214\354\260\250\354\231\200 \355\201\254\353\240\210\354\235\270.md"
new file mode 100644
index 00000000..456d5871
--- /dev/null
+++ "b/suyeun84/202509/18 PGM LV2 \354\247\200\352\262\214\354\260\250\354\231\200 \355\201\254\353\240\210\354\235\270.md"	
@@ -0,0 +1,63 @@
+```java
+import java.util.*;
+class Solution {
+    static int[][] dir = new int[][] {{1,0}, {-1,0}, {0,1}, {0,-1}};
+    static int N, M;
+    static char[][] stor;
+    public int solution(String[] storage, String[] requests) {
+        int answer = 0;
+        N = storage.length;
+        M = storage[0].length();
+        stor = new char[N][M];
+        for (int i = 0; i < N; i++) {
+            for (int j = 0; j < M; j++) {
+                stor[i][j] = storage[i].charAt(j);
+            }
+        }
+        for (String request : requests) {
+            int type = request.length();
+            if (type == 1) {
+                ArrayList<int[]> arr = new ArrayList<>();
+                for (int i = 0; i < N; i++) {
+                    for (int j = 0; j < M; j++) {
+                        if (stor[i][j] != request.charAt(0)) continue;
+                        if (i == 0 || i == N-1 || j == 0 || j == M-1 || check(i, j)) arr.add(new int[]{i, j});
+                    }
+                }
+                for (int[] a : arr) stor[a[0]][a[1]] = '0';
+            } else if (type == 2) {
+                for (int i = 0; i < N; i++) {
+                    for (int j = 0; j < M; j++) {
+                        if (stor[i][j] == request.charAt(0)) stor[i][j] = '0';
+                    }
+                }
+            }
+        }
+        for (int i = 0; i < N; i++) {
+            for (int j = 0; j < M; j++) {
+                if (stor[i][j] != '0') answer++;
+            }
+        }
+        return answer;
+    }
+    
+    static boolean check(int i, int j) {
+        boolean[][] visited = new boolean[N][M];
+        Queue<int[]> q = new LinkedList<>();
+        q.add(new int[] {i, j});
+        visited[i][j] = true;
+        while (!q.isEmpty()) {
+            int[] curr = q.poll();
+            for (int[] d : dir) {
+                int ny = curr[0] + d[0];
+                int nx = curr[1] + d[1];
+                if (ny < 0 || ny >= N || nx < 0 || nx >= M || visited[ny][nx] || stor[ny][nx] != '0') continue;
+                if (ny == 0 || ny == N-1 || nx == 0 || nx == M-1) return true;
+                q.add(new int[] {ny, nx});
+                visited[ny][nx] = true;
+            }
+        }
+        return false;
+    }
+}
+```