Merge pull request #840 from AlgorithmWithGod/LiiNi-coder

[20250907] BOJ / G5 / 적록색약 / 이인희

Author: ShinHeeEul

LiiNi-coder/202509/07 BOJ 적록색약.md

@@ -0,0 +1,60 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayDeque;
+
+public class Main {
+    private static final int[] dr = {-1, 0, 1, 0};
+    private static final int[] dc = {0, 1, 0, -1};
+
+    public static void main(String[] args) throws IOException {
+        var br = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(br.readLine());
+        char[][] normal = new char[n][n];
+        char[][] weak = new char[n][n];
+        for (int i = 0; i < n; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < n; j++) {
+                char c = line.charAt(j);
+                normal[i][j] = c;
+                weak[i][j] = (c == 'G') ? 'R' : c;
+            }
+        }
+        int normalCount = countAreas(normal, n);
+        int weakCount = countAreas(weak, n);
+
+        System.out.printf("%d %d\n", normalCount, weakCount);
+    }
+    private static int countAreas(char[][] map, int n) {
+        boolean[][] visited = new boolean[n][n];
+        int count = 0;
+        var queue = new ArrayDeque<int[]>();
+
+        for (int r = 0; r < n; r++) {
+            for (int c = 0; c < n; c++) {
+                if (visited[r][c])
+                    continue;
+                char color = map[r][c];
+                count++;
+                visited[r][c] = true;
+                queue.offer(new int[] {r, c});
+                while (!queue.isEmpty()) {
+                    int[] now = queue.poll();
+                    for (int d = 0; d < 4; d++) {
+                        int nr = now[0] + dr[d];
+                        int nc = now[1] + dc[d];
+                        if (nr >= 0 && nr < n && nc >= 0 && nc < n
+                            && !visited[nr][nc]
+                            && map[nr][nc] == color) {
+                            visited[nr][nc] = true;
+                            queue.offer(new int[] {nr, nc});
+                        }
+                    }
+                }
+            }
+        }
+        return count;
+    }
+}
+```