Submission #500112

#	Time	Username	Problem	Language	Result	Execution time	Memory
500112		kamalsharmaa9	Bitaro’s Party (JOI18_bitaro)	C++14	0 / 100	33 ms	11148 KiB

bitaro

#include<bits/stdc++.h>
using namespace std;
#define N               100050
#define ff              first
#define ss              second
#define int             long long
#define pb              push_back
#define mp              make_pair
#define pii             pair<int,int>

void c_p_c()
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

}


const int B = 150;
int not_taken[N];
vector<int>gr[N];
vector<int>grr[N];
int dp[N];
vector<pii>dist[N];

int32_t main()
{
  c_p_c();
  int n, m, q;
  cin >> n >> m >> q;
  for (int i = 1; i <= m; i++)
  {
    int a, b;
    cin >> a >> b;
    gr[a].pb(b);
    grr[b].pb(a);
  }

///// precomputation
  for (int i = 1; i <= n; i++)
  {
    int node = i;
    vector<pii>child_and_dist;
    for (auto child : grr[node])
    {
      for (auto j : dist[child])
      {
        child_and_dist.pb({j.ff + 1, j.ss});
      }
    }
    child_and_dist.pb({0, node});
    int num_taken = 0;
    sort(child_and_dist.begin(), child_and_dist.end(), greater<pii>());
    map<int, int>rep;
    for (int i = 0; i < child_and_dist.size() && num_taken < B; i++)
    {
      if (rep.find(child_and_dist[i].ss) == rep.end())
      {
        num_taken++;
        dist[node].pb({child_and_dist[i]});
        rep[child_and_dist[i].ss] = 1;
      }
    }
  }


  while (q--)
  {
    int p, q;
    cin >> p >> q;
    vector<int>not_take;
    for (int i = 1; i <= q; i++)
    {
      int r; cin >> r;
      not_take.pb(r);
      not_taken[r] = 1;
    }
    ///////////////////////////
    if (q <= B)
    {
      int ans = -1;

      for (auto i : dist[p])
      {
        if (not_taken[i.second])
          continue;
        ans = i.first;
        break;
      }
      cout << ans << '\n';
    }
    else
    {
      for (int i = 1; i <= p; i++)
      {
        dp[i] = 0;
      }
      for (int i = 1; i <= p - 1; i++)
      {
        if (not_taken[i] && dp[i] == 0)
          continue;
        for (auto child : gr[i])
        {
          dp[child] = max(dp[child], dp[i] + 1);
        }
      }
      cout << dp[p] << '\n';
    }
    for (auto i : not_take)
      not_taken[i] = 0;

  }






}

Compilation message (stderr)

bitaro.cpp: In function 'int32_t main()':
bitaro.cpp:54:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for (int i = 0; i < child_and_dist.size() && num_taken < B; i++)
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~~

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