Submission #128857

#	Time	Username	Problem	Language	Result	Execution time	Memory
128857		RockyB	Bitaro’s Party (JOI18_bitaro)	C++17	7 / 100	2054 ms	159224 KiB

bitaro

// In The Name Of The God

#include <bits/stdc++.h>

#define f first
#define s second

#define pb push_back
#define pp pop_back

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

#define rep(a, b, c) for (int (a) = (b); (a) <= (c); (a)++) 
#define per(a, b, c) for (int (a) = (b); (a) >= (c); (a)--) 

#define nl '\n'
#define ioi exit(0);

using namespace std;

const int MAX_N = (int)1e5 + 7;
const int K = 1000;
const int inf = (int)1e9 + 7;

int n, m, q;
vector <int> g[MAX_N];

int T, k;
int tmr;
int a[MAX_N], was[MAX_N], dp[MAX_N], h[MAX_N];
bool ban[MAX_N];

int calc(int v) {
  int res = -inf;
  if (was[v] == tmr) return dp[v];
  was[v] = tmr;
  if (!ban[v]) res = 0;
  for (auto to : g[v]) {
    res = max(res, calc(to) + 1);
  }
  return dp[v] = res;
}
void read() {
  cin >> T >> k;
  rep(i, 1, k) {
    cin >> a[i];
  }
}
void naive() {
  rep(i, 1, k) {
    ban[a[i]] = 1;
  }  
  ++tmr;
  int res = calc(T);
  if (res < 0) res = -1;
  cout << res << nl;
  rep(i, 1, k) {
    ban[a[i]] = 0;
  }  
}
vector < pair <int, int > > dist[MAX_N];
int used[MAX_N];
void pre() {
  rep(i, 1, n) {
    dist[i].pb({0, i});
    for (auto to : g[i]) {
      for (auto it : dist[to]) {
        dist[i].pb({it.f + 1, it.s});
      }
    }
    sort(all(dist[i]), greater < pair <int, int> > () );
    vector < pair <int, int > > nw;
    for (auto it : dist[i]) {
      if (sz(nw) < K && used[it.s] != i) {
        used[it.s] = i;
        nw.pb(it);
      }
    }
    dist[i] = nw;
  }
}
void fast() {
  int res = -1;
  rep(i, 1, k) {
    ban[a[i]] = 1;
  }
  for (auto it : dist[T]) {
    if (!ban[it.s]) {
      res = max(res, it.f);
    }
  }
  rep(i, 1, k) {
    ban[a[i]] = 0;
  }
  cout << res << nl;
  //cerr << "DA\n";
}
int main() {
  ios_base :: sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
  #ifdef IOI
    freopen ("in.txt", "r", stdin);
    freopen ("B.out", "w", stdout);
  #endif
  cin >> n >> m >> q;
  rep(i, 1, m) {
    int s, e;
    cin >> s >> e;
    g[e].pb(s);
  }
  pre();
  //for (auto it : st[2]) cerr << it.f << ' ' << it.s << nl;
  
  rep(i, 1, q) {
    read();
    if (k >= K || T <= K) naive();
    else fast();
  }
  ioi
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86