✅ 深度搜索找联通块

walking-in-maze/main.cc

@@ -0,0 +1,46 @@
+#include <iostream>
+using namespace std;
+#define MAXN 55
+
+int maze[MAXN][MAXN];
+bool visited[MAXN][MAXN] = {false};
+
+int sum = 0;
+
+int dx[4] = {0, 0, 1, -1};
+int dy[4] = {1, -1, 0, 0};
+
+bool in_range(int x, int y, int rows, int cols) {
+  return x >= 0 && x < rows && y >= 0 && y < cols;
+}
+
+void dfs(int x, int y, int rows, int cols) {
+  if (maze[x][y] == 2 || !in_range(x, y, rows, cols) || visited[x][y])
+    return;
+
+  visited[x][y] = true;
+  sum++;
+
+  for (int i = 0; i < 4; i++) {
+    int px = x + dx[i];
+    int py = y + dy[i];
+    dfs(px, py, rows, cols);
+  }
+}
+
+int main() {
+  int N, M;
+  cin >> N >> M;
+  int start_x, start_y;
+  for (int x = 0; x < N; x++) {
+    for (int y = 0; y < M; y++) {
+      cin >> maze[x][y];
+      if (maze[x][y] == 6) {
+        start_x = x;
+        start_y = y;
+      }
+    }
+  }
+  dfs(start_x, start_y, N, M);
+  cout << sum << endl;
+}