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Submission #917730

# Submission time Handle Problem Language Result Execution time Memory
917730 2024-01-28T16:53:11 Z anton Parachute rings (IOI12_rings) C++17
38 / 100
 4000 ms 93076 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);
  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 calc_cycles(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;
}
void find_ok_first(set<int>& ok){
  
  
  /*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;

    calc_cycles(ok);
    if(nbc==1){
      fill(passed.begin(), passed.end(), 0);
      for(int i = 0; i<N; i++){
        if(!passed[i]){
          find_single(i,-1, ok);
        }
      }
    }
    if(oc[3]>0){
      auto it = m.lower_bound({3, 0});
      vector<int> off(N);
      for(; it!=m.end(); ++it){
        set<int> neigs;
        for(auto e: adj[it->second]){
          off[e]++;
        }
        off[it->second]++;
      }
      set<int> pass;
      for(int i = 0; i<N; i++){
        if(off[i] == oc[3]){
          if(test_crititcal(i)){
            pass.insert(i);
          }
        }
      }
      return pass.size();
    }
    else if(nbc==0){
      return N;
    }
    
    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 1028 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 1016 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1004 KB Output is correct
10 Correct 6 ms 1116 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2198 ms 61724 KB Output is correct
2 Execution timed out 4021 ms 93076 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 1028 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 1016 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1004 KB Output is correct
10 Correct 6 ms 1116 KB Output is correct
11 Correct 16 ms 1116 KB Output is correct
12 Correct 29 ms 1628 KB Output is correct
13 Correct 45 ms 1640 KB Output is correct
14 Correct 22 ms 1624 KB Output is correct
15 Correct 28 ms 2396 KB Output is correct
16 Correct 27 ms 1592 KB Output is correct
17 Correct 26 ms 1548 KB Output is correct
18 Correct 16 ms 2492 KB Output is correct
19 Correct 27 ms 1668 KB Output is correct
20 Correct 42 ms 1624 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 1028 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 1016 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1004 KB Output is correct
10 Correct 6 ms 1116 KB Output is correct
11 Correct 16 ms 1116 KB Output is correct
12 Correct 29 ms 1628 KB Output is correct
13 Correct 45 ms 1640 KB Output is correct
14 Correct 22 ms 1624 KB Output is correct
15 Correct 28 ms 2396 KB Output is correct
16 Correct 27 ms 1592 KB Output is correct
17 Correct 26 ms 1548 KB Output is correct
18 Correct 16 ms 2492 KB Output is correct
19 Correct 27 ms 1668 KB Output is correct
20 Correct 42 ms 1624 KB Output is correct
21 Execution timed out 4019 ms 5364 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 1028 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 3 ms 1016 KB Output is correct
6 Correct 6 ms 1372 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 6 ms 1004 KB Output is correct
10 Correct 6 ms 1116 KB Output is correct
11 Correct 2198 ms 61724 KB Output is correct
12 Execution timed out 4021 ms 93076 KB Time limit exceeded
13 Halted 0 ms 0 KB -