3982. From adjacency list to adjacency matrix

/********************
* Problem: 3982.
* Theme: Graphs
*/
#include <bits/stdc++.h>

using namespace std;

#define int long long
#define mp make_pair
#define pb push_back
#define ALL(A) A.begin(),A.end()
#define RALL(A) A.rbegin(),A.rend()
#define FOR(i,a,b) for(int i=(a);i<(b);i++)

typedef vector<int> VI;
typedef vector<pair<int,int> > VII;
typedef vector<VI> VVI;

const long double PI=acos(-1);
const int INF=(int)1e18;
const int MOD=(int)1e9+7;
const int N = 1e3;

int m[101][101];

signed main()
{
    ios::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr);
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    //freopen("reform.in","r",stdin);
    //freopen("reform.out","w",stdout);

    int n;
    cin >> n;

    int t;

    int a;

    for(int i=0;i<n;i++)
    {
        cin >> t;
        while(t--)
        {
            cin >> a;
            m[i][a-1]=1;
        }
    }

    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            cout << m[i][j] << " ";
        }
        cout << "\n";
    }

    return 0;
}