これは特に悩むところはなく。これから難しくなると思うので小休憩ですね。
#include <iostream> using namespace std; static const int N = 100; static int M[N + 1][N + 1] = {}, p[N + 1] = {}; int main() { int n; cin >> n; int number, count, value; for (int i = 0; i < n; i++) { cin >> number >> count; for (int j = 0; j < count; j++) { cin >> value; M[number - 1][value - 1] = 1; } } for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (j != 0) { cout << " "; } cout << M[i][j]; } cout << endl; } return 0; }