#include <bits/stdc++.h> using namespace std; #define FOR(i, a, b) for(int i = a; i <= b; i++) #define FOD(i, a, b) for(int i = a; i >= b; i--) #define fi first #define se second #define ll long long #define db double #define ii pair<int,int> #define pb push_back #define MASK(i) (1LL << i) #define sq(i) (1LL * (i) * (i)) #define task "task" const ll INF = 1e18; const int inf = 1e9; const int N = 1e5 + 4; const int M = 2e5 + 4; const int S = 316; int n, m, q; vector<int> g[N], topo; vector<ii> lp[N], can[N]; int dp[N]; bool in[N]; void lightset(int t, int y, vector<int> &ban) { for(int x : ban) in[x] = 1; for(ii x : lp[t]) { if(!in[x.se]) { cout << x.fi << '\n'; for(int tmp : ban) in[tmp] = 0; return; } } for(int x : ban) in[x] = 0; cout << -1 << '\n'; } void heavyset(int t, int y, vector<int> &ban) { FOR(i, 1, n) dp[i] = 0; for(int x : ban) dp[x] = -1; FOR(u, 1, n) { if(dp[u] == -1) continue; for(int v : g[u]) dp[v] = max(dp[v], dp[u] + 1); } cout << dp[t] << '\n'; } signed main() { if(fopen(task".inp", "r")) { freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); } ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); cin >> n >> m >> q; FOR(i, 1, m) { int u, v; cin >> u >> v; g[u].pb(v); } FOR(i, 1, n) can[i].pb({0, i}); FOR(u, 1, n) { sort(can[u].begin(), can[u].end(), greater<ii>()); for(ii x : can[u]) { if(!in[x.se]) { in[x.se] = 1; lp[u].pb(x); } if(lp[u].size() > S + 1) break; } assert(lp[u].size() <= S + 1); can[u].clear(); for(ii x : lp[u]) in[x.se] = 0; for(int v : g[u]) { for(ii x : lp[u]) { can[v].pb({x.fi + 1, x.se}); } } } FOR(i, 1, q) { int t, y; cin >> t >> y; vector<int> ban; FOR(j, 1, y) { int x; cin >> x; ban.pb(x); } if(y <= S) lightset(t, y, ban); else heavyset(t, y, ban); } }

bitaro.cpp: In function 'int main()':
bitaro.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:53:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~