✅ 暴力深度优先搜索解决翻卡片

flip-card/main.cc

@@ -0,0 +1,69 @@
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+using namespace std;
+
+const int N = 50;
+
+char tiles[N + 5][N + 5];
+bool visited[N + 5][N + 5];
+
+int dx[4] = {-1, 1, 0, 0};
+int dy[4] = {0, 0, -1, 1};
+
+bool in_range(int x, int y, int rows, int cols) {
+  return x >= 0 && x < rows && y >= 0 && y < cols;
+}
+
+int dfs(int x, int y, int rows, int cols) {
+  if (!in_range(x, y, rows, cols) || visited[x][y] || tiles[x][y] == 'B') {
+    return 0;
+  }
+
+  visited[x][y] = true;
+  int size = 1;
+
+  for (int i = 0; i < 4; ++i) {
+    int px = x + dx[i];
+    int py = y + dy[i];
+
+    size += dfs(px, py, rows, cols);
+  }
+
+  return size;
+}
+
+int find_largest_area(int rows, int cols) {
+  int max_size = 0;
+
+  for (int i = 0; i < rows; i++) {
+    for (int j = 0; j < cols; j++) {
+      if (!visited[i][j] && tiles[i][j] == 'A') {
+        int size = dfs(i, j, rows, cols);
+        max_size = max(max_size, size);
+      }
+    }
+  }
+
+  return max_size;
+}
+
+int main() {
+  int n;
+  cin >> n;
+  for (int x = 0; x < n; x++)
+    for (int y = 0; y < n; y++)
+      cin >> tiles[x][y];
+  int max_chunk = 0;
+  for (int x = 0; x < n; x++) {
+    for (int y = 0; y < n; y++) {
+      if (tiles[x][y] == 'A')
+        continue;
+      tiles[x][y] = 'A';
+      memset(visited, 0, sizeof visited);
+      max_chunk = max(max_chunk, find_largest_area(n, n));
+      tiles[x][y] = 'B';
+    }
+  }
+  cout << max_chunk << endl;
+}