Language: C++

#include <bits/stdc++.h>
using namespace::std;

#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()

typedef long long ll;
typedef array<int, 3> tri;
typedef array<int, 2> duo;
typedef long double ld;

template <class T> istream& operator>>(istream& I, vector<T>& v) {for (T &e: v) I >> e; return I;}
template <class T> ostream& operator<<(ostream &O, const vector<T>& v) {for (const T &e: v) O << e << ' '; return O;}




bool dfs(int now, vector<vector<pair<int,int>>>& t, vector<int>& status) {
        if (status[now] == 1) return 1;
        if (!status[now]) return 0;
        status[now] = 1;
        bool ok = 1;
        for (auto it: t[now]) {
                if (it.second) ok |= dfs(it.first, t, status);
                else if (status[it.first] == 1) return 0;
        }
        return ok;
}


void _main() {
        int n; cin >> n;
        vector<vector<pair<int,int>>> t(n);
        for (int i = 0; i < n; i++) {
                int x; cin >> x;
                while (x--) {
                        int a, b; cin >> a >> b;
                        a--;
                        t[i].emplace_back(a, b);
                }
        }

        int ans = 0;
        for (int i = 0; i < n; i++) {
                vector<int> status(n, -1);
                auto res = dfs(i, t, status);
                if (res) {
                        ans = max(ans, count(all(status), 1));
                }
        }

        cout << ans << '\n';
}



signed main() {
        ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//        freopen("input.txt", "r", stdin);
        int _t = 1;
//        cin >> _t;
        while (_t--) _main();
        return 0;
}


Compiler output:
a.cc: In function 'void _main()':
a.cc:48:34: error: no matching function for call to 'max(int&, std::__iterator_traits<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, void>::difference_type)'
   48 |                         ans = max(ans, count(all(status), 1));
      |                               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:48:34: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'std::__iterator_traits<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, void>::difference_type' {aka 'long int'})
   48 |                         ans = max(ans, count(all(status), 1));
      |                               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:48:34: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   48 |                         ans = max(ans, count(all(status), 1));
      |                               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~