1ms很慢吗？

#include <iostream>
#include <vector>
using namespace std;
const int MOD = 1e9 + 7;
int n, m;
vector<string> grid;
bool isValidLPart(int x1, int y1, int x2, int y2) {
return true;
}
void placeL(int x, int y, int& count) {
if (x < 0 || x >= n || y < 0 || y >= m || grid[x][y] == '#') return;
grid[x][y] = '#';
for (int dx = -1; dx <= 1; ++dx) {
for (int dy = -1; dy <= 1; ++dy) {
if (dx == 0 && dy == 0) continue;
if (isValidLPart(x, y, x + dx, y + dy)) {
placeL(x + dx, y + dy, count);
}
}
}
grid[x][y] = '.';
}

int main() {
cin >> n >> m;
grid.resize(n);
for (int i = 0; i < n; ++i) {
cin >> grid[i];
}

int count = 0;  
for (int i = 0; i < n; ++i) {  
    for (int j = 0; j < m; ++j) {  
        if (grid[i][j] == '.') {  
            placeL(i, j, count);  
            count %= MOD; 
        }  
    }  
}  
  
cout << count << endl;  
return 0;  

}