Submission #455204

#	Time	Username	Problem	Language	Result	Execution time	Memory
455204		czhang2718	Bitaro’s Party (JOI18_bitaro)	C++17	7 / 100	1191 ms	524292 KiB

bitaro

#include "bits/stdc++.h"
using namespace std;

#define f first
#define s second
typedef pair<int, int> pii;
#define nl '\n'

const int B=850;
int n, q, m;
vector<int> adj[100001];
vector<int> radj[100001];
unordered_map<int, int> C[100001];
pii best[100001][B+2];
int ind[100001];
int t[100001];
vector<int> batch[100001];
vector<int> sep;
int ans[100001];
int dp[100001];
int used[100001];

int main(){
  cin.tie(0)->sync_with_stdio(0);
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);

  cin >> n >> m >> q;

  for(int i=1; i<=m; i++){
    int u, v; cin >> u >> v;
    adj[u].push_back(v);
    radj[v].push_back(u);
  }
  for(int i=1; i<=q; i++){
    int y;
    cin >> t[i] >> y;
    C[i].reserve(y);
    for(int j=1; j<=y; j++) {
      int c; cin >> c;
      C[i][c]=1;
    }
    if(y<=B) batch[t[i]].push_back(i);
    else sep.push_back(i);
  }

  for(int i=1; i<=n; i++){
    int j=1;
    for(int u:radj[i]) ind[u]=1;
    while(j<=B+1){
      pii use={-1, -1};
      for(int u:radj[i]){
        while(used[best[u][ind[u]].s]==i && ind[u]<=B+1) ind[u]++;
        if(ind[u]>B+1 || !best[u][ind[u]].s) continue;
        use=max(use, best[u][ind[u]]);
      }
      if(use.f==-1) break;
      used[use.s]=i;
      best[i][j]={use.f+1, use.s};
      j++;
    }
    if(j<=B+1) best[i][j]={0, i};

    for(int j:batch[i]){
      int k=1;
      while(C[j][best[i][k].s]) k++;
      if(!best[i][k].s) ans[j]=-1;
      else ans[j]=best[i][k].f;
    }
  }

  for(int j:sep){
    ans[j]=(C[j].find(t[j])==C[j].end())-1;
    dp[t[j]]=0;
    for(int i=t[j]-1; i>=1; i--){
      dp[i]=-1;
      for(auto k:adj[i]) if(k<=t[j] && dp[k]!=-1) dp[i]=max(dp[i], dp[k]+1);
      if(C[j].find(i)==C[j].end()) ans[j]=max(ans[j], dp[i]);
    }
  }

  for(int i=1; i<=q; i++) cout << ans[i] << '\n';
}

// mp.find

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