oj.uz

Submission #917718

# Submission time Handle Problem Language Result Execution time Memory
917718 2024-01-28T16:41:47 Z anton Parachute rings (IOI12_rings) C++17
38 / 100
 4000 ms 93312 KB 
#include<bits/stdc++.h>
using namespace std;

#define int long long
#define pii pair<int, int>

int N;
vector<vector<int>> adj;
vector<bool> passed;
vector<bool> cur_in;
set<pii> m;
vector<int> oc;



void Init(signed N_) {
  N = N_;
  oc.resize(5);
  adj.resize(N);
  cur_in.resize(N);
  passed.resize(N, false);
  set<int> l;
  for(int i= 0; i<N; i++){
    m.insert({0, i});
    oc[0]++;
  }
}
int flored(int id){
  return min(4LL, id);
}

void Link(signed A, signed B) {
  m.erase({adj[A].size(), A});
  m.erase({adj[B].size(), B});
  oc[flored(adj[A].size())]--;
  oc[flored(adj[B].size())]--;


  adj[A].push_back(B);
  adj[B].push_back(A);

  oc[flored(adj[A].size())]++;
  oc[flored(adj[B].size())]++;

  m.insert({adj[A].size(), A});
  m.insert({adj[B].size(), B});
}

int forbiden = 0;

bool dfs(int id, int anc){
  passed[id] = true;
  bool ok = true;
  for(auto v: adj[id]){
    if(v!=forbiden && v!=anc){
      if(passed[v]){
        return false;
      }
      else{
        ok &= dfs(v, id);
      }
    }
  }
  return ok;
}
bool test_crititcal(int id){
  forbiden = id;
  for(int i = 0; i<N; i++){  
    int deg =0;
    if(i == id){
      continue;
    }
    for(auto e: adj[i]){
      if(e!=id){
        deg++;
      }
    }
    if(deg>2){
      ////cout<<"deg "<<endl;
      return false;
    }
  }
  fill(passed.begin(), passed.end(), false);
  for(int i=  0; i<N; i++){
    if(!passed[i] && i!=forbiden){
      if(!dfs(i, -1)){
        ////cout<<"cycle "<<endl;
        return false;
      }
    }
  }
  return true;
}
int nbc = 0;

void nb_cycles(int u, int prev){
  passed[u] = true;
  for(auto v: adj[u]){
    if(v==prev){
      continue;
    }
    if(passed[v]){
      nbc++;
      //cout<<u<<" "<<v<<endl;
    }
    else{
      nb_cycles(v, u);
    }
  }
}
int find_intersection(int u, set<int>& res, int prev){
  passed[u] = true;
  cur_in[u] = true;
  int cur = 0;
  int ending = 0;
  bool founder = false;
  for(auto v: adj[u]){
    if(v==prev){
      continue;
    }
    if(passed[v]){
      //cout<<u<<" "<<v<<endl;
      if(cur_in[v]){
        cur++;
      }
      else{
        ending--;
      }
    }
    else{
      int child =find_intersection(v, res, u);
      if(child!=nbc){
        founder =true;
      }
      cur +=child; 
    }
  }
  if(cur == nbc && (ending !=0 || founder)){
    res.insert(u);
  }
  cur+=ending;
  cur_in[u] =false;
  return cur;
}
pair<bool, int> find_single(int u, int a, set<int>& s){
  passed[u] = true;
  for(auto v: adj[u]){
    if(v!=a){
      if(passed[v]){
        s.insert(u);
        return {true, v};
      }
      else{
        auto res = find_single(v, u, s);
        if(res.second == u){
          s.insert(u);
          return {false, -1};
        }
        else{
          if(res.first){
            s.insert(u);
            return res;
          }
        }
      }
    }
  }
  return {false, -1};
}
void find_ok_first(set<int>& ok){
  fill(passed.begin(), passed.end(), 0);
  nbc= 0;
  for(int i = 0; i<N; i++){
    if(!passed[i]){
      nb_cycles(i,-1);
    }
  }
  nbc/=2;
  //cout<<"nbc "<<nbc<<endl;
  if(nbc==1){
    fill(passed.begin(), passed.end(), 0);
    for(int i = 0; i<N; i++){
      if(!passed[i]){
        find_single(i,-1, ok);
      }
    }
  }
  else if(oc[3]>0 || nbc == 0){
    for(int i = 0; i<N; i++){
      ok.insert(i);
    }
  }
  /*cout<<"ok "<<endl;
  for(auto e: ok){
    cout<<e<<" ";
  }
  cout<<endl;*/
}
signed CountCritical() {
  int res= 0;
  if(oc[4]>1){
    return 0;
  }
  else if(oc[4] == 1){
    int cand = m.lower_bound({4, 0})->second;
    if(test_crititcal(cand)){
      res++;
    }
    return res;
  }
  else{
    set<int> ok;

    find_ok_first(ok);

    if(oc[3]>0){
      auto it = m.lower_bound({3, 0});
      for(; it!=m.end(); ++it){
        set<int> neigs;
        for(auto e: adj[it->second]){
          neigs.insert(e);
        }
        neigs.insert(it->second);
        vector<int> rem;
        for(auto e: neigs){
          if(ok.find(e) == ok.end()){
            rem.push_back(e);
          }
        }
        for(auto e: rem){
          neigs.erase(e);
        }
        swap(ok, neigs);
      }
      set<int> pass;
      for(auto e: ok){
        if(test_crititcal(e)){
          pass.insert(e);
        }
      }
      swap(pass, ok);
    }
    
    return ok.size();
  }

}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 4 ms 860 KB Output is correct
3 Correct 5 ms 860 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 860 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 1116 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1368 KB Output is correct
10 Correct 6 ms 1112 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2482 ms 86064 KB Output is correct
2 Execution timed out 4088 ms 93312 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 4 ms 860 KB Output is correct
3 Correct 5 ms 860 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 860 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 1116 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1368 KB Output is correct
10 Correct 6 ms 1112 KB Output is correct
11 Correct 29 ms 1116 KB Output is correct
12 Correct 111 ms 2024 KB Output is correct
13 Correct 111 ms 2212 KB Output is correct
14 Correct 22 ms 1780 KB Output is correct
15 Correct 34 ms 2392 KB Output is correct
16 Correct 98 ms 2212 KB Output is correct
17 Correct 112 ms 2116 KB Output is correct
18 Correct 56 ms 3164 KB Output is correct
19 Correct 108 ms 2132 KB Output is correct
20 Correct 121 ms 2188 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 4 ms 860 KB Output is correct
3 Correct 5 ms 860 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 860 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 1116 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1368 KB Output is correct
10 Correct 6 ms 1112 KB Output is correct
11 Correct 29 ms 1116 KB Output is correct
12 Correct 111 ms 2024 KB Output is correct
13 Correct 111 ms 2212 KB Output is correct
14 Correct 22 ms 1780 KB Output is correct
15 Correct 34 ms 2392 KB Output is correct
16 Correct 98 ms 2212 KB Output is correct
17 Correct 112 ms 2116 KB Output is correct
18 Correct 56 ms 3164 KB Output is correct
19 Correct 108 ms 2132 KB Output is correct
20 Correct 121 ms 2188 KB Output is correct
21 Execution timed out 4027 ms 7800 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 4 ms 860 KB Output is correct
3 Correct 5 ms 860 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 860 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 1116 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1368 KB Output is correct
10 Correct 6 ms 1112 KB Output is correct
11 Correct 2482 ms 86064 KB Output is correct
12 Execution timed out 4088 ms 93312 KB Time limit exceeded
13 Halted 0 ms 0 KB -