AcWing 1098. 城堡问题

题目链接 AcWing1098. 城堡问题

#include <iostream>
#include <cstring>
#include <algorithm>
#define x first
#define y second

using namespace std;

typedef pair<int, int> PII;

const int N = 55;

int n, m;
int g[N][N];
bool st[N][N];
PII q[N * N];

int bfs(int sx, int sy)
{
    int dx[4] = {0, -1, 0, 1}, dy[4] = {-1, 0, 1, 0};
    st[sx][sy] = true;
    int hh = 0, tt = 0;
    q[0] = {sx, sy};
    int area = 0;
    
    while(hh <= tt)
    {
        PII t = q[hh ++];
        area ++;
        for(int i = 0; i < 4; i ++)
        {
            int a = dx[i] + t.x, b = dy[i] + t.y;
            if(a >= n || a < 0 || b < 0 || b >= m) continue;
            if(st[a][b]) continue;
            if(g[t.x][t.y] >> i & 1) continue;
            
            q[++ tt] = {a, b};
            st[a][b] = true;
        }
    }
    return area;
}

int main()
{
    cin >> n >> m;
    for (int i = 0; i < n; i ++ )
        for(int j = 0; j < m; j ++)
            cin >> g[i][j];
            
    int cnt = 0, area = 0;
    for(int i = 0; i < n; i ++)
        for(int j = 0; j < m; j ++)
        {
            if(!st[i][j])
            {
                area = max(bfs(i, j), area);
                cnt ++;                
            }

        }
    cout << cnt << endl;
    cout << area << endl;
    
}