oj.uz

Submission #1020140

# Submission time Handle Problem Language Result Execution time Memory
1020140 2024-07-11T15:36:48 Z anton Parachute rings (IOI12_rings) C++17
55 / 100
 4000 ms 262144 KB 
#include<bits/stdc++.h>

using namespace std;


int nbCycles = 0;
int szCycle= 0;

struct DSU{
  int nbGroups =0;
  vector<int> anc;
  vector<int> sz;
  vector<pair<int, pair<int, int>>> op_buffer;

  DSU(){};
  DSU(int l){
    anc.resize(l);
    sz.resize(l);
    for(int i = 0; i<l; i++){
      anc[i] = i;
      sz[i] = 1;
    }
    nbGroups = l;
  }
  int c(int u){
    op_buffer.push_back({u, {anc[u], sz[u]}});
    if(anc[u] == u){
      return u;
    }
    int v= c(anc[u]);
    anc[u] =v;
    return v;
  }

  void merge(int a, int b){
    //cerr<<"merging "<<a<<" "<<b<<endl;
    a = c(a);
    b= c(b);
    if(a==b){
      nbCycles ++;
      szCycle = sz[a];
      return;
    }
    nbGroups--;

    op_buffer.push_back({a, {anc[a], sz[a]}});
    op_buffer.push_back({b, {anc[b], sz[b]}});

    if(sz[a]>sz[b]){
      swap(a, b);
    }

    anc[a] = b;
    sz[b] += sz[a];  
  }

  void undo_buffer(){
    while(op_buffer.size()>0){
      auto e= op_buffer.back();
      if(anc[e.first] == e.first){
        nbGroups--;
      }
      op_buffer.pop_back();
      anc[e.first] = e.second.first;
      sz[e.first] = e.second.second;
      if(anc[e.first] == e.first){
        nbGroups++;
      }
    }
  }
};

int N;
const int MAX_N= 1e6;
vector<int> adj[MAX_N];
vector<int> interesting;
bool isInteresting[MAX_N];
int deg[MAX_N], oc[MAX_N];

DSU curDSU;
int above3= 0;
int above4 = 0;


DSU recalcDSU(){
  DSU newDSU(N);
  for(int iV = 0; iV<N; iV++){
    
      for(auto u: adj[iV]){
        if(!(isInteresting[u] || isInteresting[iV])){
          newDSU.merge(iV, u);
        }
      }
    
  }

  newDSU.op_buffer.clear();
  return newDSU;
}

bool lost3 = false;

int count3(int u){
  int res= 0;
  for(auto e: adj[u]){
    if(deg[e]>=3){
      res++;
    }
  }
  return res;
}
void changeDeg(int u, int d){
  
  if(deg[u]>=3){
    above3--;
  }
  if(deg[u] >= 4){
    above4--;
  }
  oc[deg[u]]--;
  deg[u] +=d;
  oc[deg[u]] ++;
  if(deg[u]>=3){
    above3++;
  }
  if(deg[u] >= 4){
    above4++;
  }
}


void Init(int N_) {

  
  N = N_;
  fill(&oc[0], &oc[N], 0);
  oc[0]  =N;

  curDSU = DSU(N);

}

bool check_possible(){

  if(interesting.size() == 0){
    return true;
  }
  unordered_map<int, int> m;
  int target = 0;

  for(auto e: interesting){
    if(deg[e] == 3){
    
      for(auto ee: adj[e]){
        m[ee]++;
      }
      m[e]++;
      target++;

    }
  }

  for(auto e: m){
    if(e.second == target){
      return true;
    }
  }
  return false;

  
}

bool changed = true;

void clear_interesting(){
  vector<int> new_interesting;
  for(auto e: interesting){
    if(deg[e] != 4){
      isInteresting[e] = false;
    }
    else{
      new_interesting.push_back(e);
    }
  }

  for(auto e: interesting){
    for(auto ee: adj[e]){

      if(!(isInteresting[ee] ||isInteresting[e])){
        curDSU.merge(e, ee);
      }
    }
  }

  swap(interesting, new_interesting);
}

void Link(int A, int B) {
  changed = true;
  if(above4>1 || lost3){
    return;
  }

  adj[A].push_back(B);
  changeDeg(A, +1);
  adj[B].push_back(A);
  changeDeg(B, +1);
  if(above4 == 0 && (deg[A]== 3 || deg[B]==3)){

    if(deg[A] != 3){
      swap(A, B);
    }
    if(!isInteresting[A]){
      isInteresting[A] = true;
      interesting.push_back(A);
    }
    for(auto e: adj[A]){
      if(!isInteresting[e]){
        isInteresting[e] = true;
        interesting.push_back(e);
      }
    }
    if(deg[B] == 3){
      if(!isInteresting[B]){
        isInteresting[B] = true;
        interesting.push_back(B);
      }
      for(auto e: adj[B]){
        if(!isInteresting[e]){
          isInteresting[e] = true;
          interesting.push_back(e);
        }
      }
    }
    curDSU = recalcDSU();
  }
  else if(isInteresting[A] || isInteresting[B]){

  }
  else{
    curDSU.merge(A, B);
    curDSU.op_buffer.clear();
  }

  if((deg[A] == 4 || deg[B]== 4) && above4 == 1){
    clear_interesting();
  }

  if(deg[A]>=4){
    if(count3(A)<above3-1){
      lost3 = true;
    }
  }
  if(deg[B]>=4){
    if(count3(B)<above3-1){
      lost3 = true;
    }
  }

  if(above4 == 0){
    if(!check_possible()){
      lost3 = true;
    }
  }
}

int prev_res=  0;

int calc(){
  if(above4>1 || lost3){
    return 0;
  }
  else{
    if(above3>=1){
      int res= 0;


      for(auto iAdd: interesting){
        for(auto e: adj[iAdd]){
          if(!isInteresting[e]){
            changeDeg(e, -1);
          }
          changeDeg(iAdd, -1);
        }
      }


      for(auto iRem: interesting){
        if(deg[iRem]>=4 || above4 ==0){
          for(auto iAdd: interesting){
            if(iAdd!=iRem){
              for(auto e: adj[iAdd]){
                if(e!=iRem){
                  curDSU.merge(e, iAdd);
                  if(!isInteresting[e]){
                    changeDeg(e, 1);
                  }
                  changeDeg(iAdd, 1);
                }
              }
            }
          }

          
          if((oc[0]-1)*2 + oc[1] == (curDSU.nbGroups-1)*2 && above3 ==0){
            res++;
          }


          for(auto iAdd: interesting){
            if(iAdd!=iRem){
              for(auto e: adj[iAdd]){
                if(e!=iRem){
                  if(!isInteresting[e]){
                    changeDeg(e, -1);
                  }
                  changeDeg(iAdd, -1);
                }
              }
            }
          }
          curDSU.undo_buffer();
        }
      }


      for(auto iAdd: interesting){
        for(auto e: adj[iAdd]){
          if(!isInteresting[e]){
            changeDeg(e, 1);
          }
          changeDeg(iAdd, 1);
        }
      }
      return res;
    }
    else{
      if(nbCycles == 0){
        return N;
      }
      else if(nbCycles == 1){
        return szCycle;
      }
      else{
        return 0;
      }
    }
  }
}

int CountCritical() {
  if(!changed){
    return prev_res;
  }
  prev_res = calc();
  return prev_res;

}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23900 KB Output is correct
2 Correct 13 ms 24424 KB Output is correct
3 Correct 12 ms 24140 KB Output is correct
4 Correct 12 ms 23900 KB Output is correct
5 Correct 11 ms 24108 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 24152 KB Output is correct
8 Correct 12 ms 24156 KB Output is correct
9 Correct 12 ms 24852 KB Output is correct
10 Correct 12 ms 25340 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 244 ms 55100 KB Output is correct
2 Correct 583 ms 94988 KB Output is correct
3 Correct 195 ms 53904 KB Output is correct
4 Correct 759 ms 84216 KB Output is correct
5 Correct 795 ms 84048 KB Output is correct
6 Correct 823 ms 82664 KB Output is correct
7 Correct 182 ms 54460 KB Output is correct
8 Correct 1274 ms 241880 KB Output is correct
9 Correct 1489 ms 262144 KB Output is correct
10 Correct 495 ms 81620 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23900 KB Output is correct
2 Correct 13 ms 24424 KB Output is correct
3 Correct 12 ms 24140 KB Output is correct
4 Correct 12 ms 23900 KB Output is correct
5 Correct 11 ms 24108 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 24152 KB Output is correct
8 Correct 12 ms 24156 KB Output is correct
9 Correct 12 ms 24852 KB Output is correct
10 Correct 12 ms 25340 KB Output is correct
11 Correct 20 ms 25840 KB Output is correct
12 Correct 19 ms 28212 KB Output is correct
13 Correct 18 ms 27876 KB Output is correct
14 Correct 24 ms 24212 KB Output is correct
15 Correct 29 ms 24408 KB Output is correct
16 Correct 14 ms 24408 KB Output is correct
17 Correct 13 ms 24408 KB Output is correct
18 Correct 13 ms 24668 KB Output is correct
19 Correct 14 ms 24532 KB Output is correct
20 Correct 16 ms 26196 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23900 KB Output is correct
2 Correct 13 ms 24424 KB Output is correct
3 Correct 12 ms 24140 KB Output is correct
4 Correct 12 ms 23900 KB Output is correct
5 Correct 11 ms 24108 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 24152 KB Output is correct
8 Correct 12 ms 24156 KB Output is correct
9 Correct 12 ms 24852 KB Output is correct
10 Correct 12 ms 25340 KB Output is correct
11 Correct 20 ms 25840 KB Output is correct
12 Correct 19 ms 28212 KB Output is correct
13 Correct 18 ms 27876 KB Output is correct
14 Correct 24 ms 24212 KB Output is correct
15 Correct 29 ms 24408 KB Output is correct
16 Correct 14 ms 24408 KB Output is correct
17 Correct 13 ms 24408 KB Output is correct
18 Correct 13 ms 24668 KB Output is correct
19 Correct 14 ms 24532 KB Output is correct
20 Correct 16 ms 26196 KB Output is correct
21 Correct 22 ms 25944 KB Output is correct
22 Correct 31 ms 27228 KB Output is correct
23 Correct 37 ms 28220 KB Output is correct
24 Execution timed out 4046 ms 27832 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23900 KB Output is correct
2 Correct 13 ms 24424 KB Output is correct
3 Correct 12 ms 24140 KB Output is correct
4 Correct 12 ms 23900 KB Output is correct
5 Correct 11 ms 24108 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 24152 KB Output is correct
8 Correct 12 ms 24156 KB Output is correct
9 Correct 12 ms 24852 KB Output is correct
10 Correct 12 ms 25340 KB Output is correct
11 Correct 244 ms 55100 KB Output is correct
12 Correct 583 ms 94988 KB Output is correct
13 Correct 195 ms 53904 KB Output is correct
14 Correct 759 ms 84216 KB Output is correct
15 Correct 795 ms 84048 KB Output is correct
16 Correct 823 ms 82664 KB Output is correct
17 Correct 182 ms 54460 KB Output is correct
18 Correct 1274 ms 241880 KB Output is correct
19 Correct 1489 ms 262144 KB Output is correct
20 Correct 495 ms 81620 KB Output is correct
21 Correct 20 ms 25840 KB Output is correct
22 Correct 19 ms 28212 KB Output is correct
23 Correct 18 ms 27876 KB Output is correct
24 Correct 24 ms 24212 KB Output is correct
25 Correct 29 ms 24408 KB Output is correct
26 Correct 14 ms 24408 KB Output is correct
27 Correct 13 ms 24408 KB Output is correct
28 Correct 13 ms 24668 KB Output is correct
29 Correct 14 ms 24532 KB Output is correct
30 Correct 16 ms 26196 KB Output is correct
31 Correct 22 ms 25944 KB Output is correct
32 Correct 31 ms 27228 KB Output is correct
33 Correct 37 ms 28220 KB Output is correct
34 Execution timed out 4046 ms 27832 KB Time limit exceeded
35 Halted 0 ms 0 KB -