oj.uz

Submission #917726

# Submission time Handle Problem Language Result Execution time Memory
917726 2024-01-28T16:49:06 Z anton Parachute rings (IOI12_rings) C++17
38 / 100
 4000 ms 93136 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});

      set<int> neigs;
      for(auto e: adj[it->second]){
        ok.insert(e);
      }
      ok.insert(it->second);
      it++;
      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);
    }
    else if(nbc==0){
      return N;
    }
    
    return ok.size();
  }

}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 5 ms 860 KB Output is correct
3 Correct 5 ms 1072 KB Output is correct
4 Correct 2 ms 500 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 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 5 ms 1116 KB Output is correct
10 Correct 6 ms 856 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2392 ms 61680 KB Output is correct
2 Execution timed out 4027 ms 93136 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 5 ms 860 KB Output is correct
3 Correct 5 ms 1072 KB Output is correct
4 Correct 2 ms 500 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 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 5 ms 1116 KB Output is correct
10 Correct 6 ms 856 KB Output is correct
11 Correct 16 ms 856 KB Output is correct
12 Correct 30 ms 1876 KB Output is correct
13 Correct 53 ms 1648 KB Output is correct
14 Correct 25 ms 1540 KB Output is correct
15 Correct 27 ms 2396 KB Output is correct
16 Correct 26 ms 1880 KB Output is correct
17 Correct 29 ms 1628 KB Output is correct
18 Correct 15 ms 2652 KB Output is correct
19 Correct 28 ms 1628 KB Output is correct
20 Correct 45 ms 1792 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 5 ms 860 KB Output is correct
3 Correct 5 ms 1072 KB Output is correct
4 Correct 2 ms 500 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 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 5 ms 1116 KB Output is correct
10 Correct 6 ms 856 KB Output is correct
11 Correct 16 ms 856 KB Output is correct
12 Correct 30 ms 1876 KB Output is correct
13 Correct 53 ms 1648 KB Output is correct
14 Correct 25 ms 1540 KB Output is correct
15 Correct 27 ms 2396 KB Output is correct
16 Correct 26 ms 1880 KB Output is correct
17 Correct 29 ms 1628 KB Output is correct
18 Correct 15 ms 2652 KB Output is correct
19 Correct 28 ms 1628 KB Output is correct
20 Correct 45 ms 1792 KB Output is correct
21 Execution timed out 4062 ms 6008 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 5 ms 860 KB Output is correct
3 Correct 5 ms 1072 KB Output is correct
4 Correct 2 ms 500 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 860 KB Output is correct
8 Correct 4 ms 860 KB Output is correct
9 Correct 5 ms 1116 KB Output is correct
10 Correct 6 ms 856 KB Output is correct
11 Correct 2392 ms 61680 KB Output is correct
12 Execution timed out 4027 ms 93136 KB Time limit exceeded
13 Halted 0 ms 0 KB -