AC

#include <bits/stdc++.h>
using namespace std;
int n,ans;
int mp[1005][1005]; 
int dx[8]={-1,0,0,1};
int dy[8]={0,-1,1,0};
void dfs(int x,int y){
	for(int i=0;i<4;i++){
		int nx=x+dx[i];
		int ny=y+dy[i];
		if(nx>=0&&nx<=n+1&&ny>=0&&ny<=n+1&&mp[nx][ny]==0){
			mp[nx][ny]=-1;
			dfs(nx,ny);
		}
	}
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
    	for(int j=1;j<=n;j++){
    		cin>>mp[i][j];
		}
	}
    mp[0][0]=-1;
    dfs(0,0);
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(mp[i][j]==-1) cout<<"0"<<" ";
            if(mp[i][j]==0) cout<<"2"<<" ";
            if(mp[i][j]==1) cout<<"1"<<" ";
        }
        cout<<endl;
    }
    return 0;
}