J. Robot Factory

#include <bits/stdc++.h>

using namespace std;
using pi = pair <int, int>;
using pii = pair <int, pi>;
const int N = 1e3 + 10;
const int M = 1e3 + 10;
int di[] = {0, 1, 0, -1};
int dj[] = {-1, 0, 1, 0};
int ar[N][M];
bool vs[N][M];
int n, m;

int Size(int ui, int uj){
    vs[ui][uj] = true;
    int dis = 1;
    for(int dij = 0, drt = ar[ui][uj]; dij < 4; dij ++, drt >>= 1){
        int vi = ui + di[dij];
        int vj = uj + dj[dij];
        if((drt&1) == 0 and !vs[vi][vj])
            dis += Size(vi, vj);
    }
    return dis;
}

int main(){

    scanf("%d%d", &n, &m);

    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            scanf("%d", &ar[i][j]);
        }
    }

    vector <int> room;

    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            if(!vs[i][j])
                room.push_back(Size(i, j));
        }
    }

    sort(room.begin(), room.end());
    int sz = room.size();
    for(int i=sz-1;i>=0;i--)
        printf("%d ", room[i]);

    return 0;
}