oj.uz

Submission #1020234

# Submission time Handle Problem Language Result Execution time Memory
1020234 2024-07-11T17:55:00 Z anton Parachute rings (IOI12_rings) C++17
38 / 100
 4000 ms 11728 KB 
#include<bits/stdc++.h>

using namespace std;

struct DSU{
  int nbGroups =0;
  bool needs_op_buffer = false;
  vector<int> anc;
  vector<int> sz;
  vector<pair<int, pair<int, int>>> op_buffer;
  int nbCycles = 0;
  int szCycle= 0;

  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){
    
    if(needs_op_buffer)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--;

    if(needs_op_buffer)op_buffer.push_back({a, {anc[a], sz[a]}});
    if(needs_op_buffer)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= 1e5;
vector<int> adj[MAX_N];
unordered_set<int> interesting;
bool isInteresting[MAX_N];
int deg[MAX_N], oc[MAX_N];

DSU boringDSU, fullDSU;
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;
}

int state = 0;
//0 = only deg<=2
//1 only deg <=3, some interesting left
//2 One deg =4, some interesting
//3 no interesting left
void changeDeg(int u, int d){
  
  if(deg[u]>=3){
    above3--;
  }
  if(deg[u] >= 4){
    above4--;
  }
  oc[deg[u]]--;
  deg[u] +=d;
  assert(deg[u]>=0);
  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);
  fill(&isInteresting[0], &isInteresting[N], true);

  for(int i = 0; i<N; i++){
    interesting.insert(i);
  }
  oc[0]  =N;
  boringDSU = DSU(N);
  fullDSU = DSU(N);
  boringDSU.needs_op_buffer = true;
}

void updInteresting(int u, bool tolerant){
  unordered_set<int> close;
  if(tolerant){
    for(auto e: adj[u]){
        close.insert(e);
    }
  }
  close.insert(u);
  for(auto it = interesting.begin(); it!=interesting.end(); ){
    if(close.find(*it)  == close.end()){
      isInteresting[*it] = false;
      //cerr<<"removing "<<*it<<endl;
      for(auto ee: adj[*it]){
        if(!isInteresting[ee]){
          boringDSU.merge(*it, ee);
        }
      }
      it = interesting.erase(it);
    }
    else{
      ++it;
    }
  }
}

void recalcDeg(){
    for(int i = 0; i<N; i++){
        if(deg[i] < 4){
          changeDeg(i, -deg[i]);
          for(auto v: adj[i]){
              if(deg[v] != 4){
                   changeDeg(i, 1);
              }
          }
        }
    }
}

void Link(int A, int B) {
    if(interesting.size()== 0){
        return;
    }

    fullDSU.merge(A, B);

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

    if(deg[A] <4 && deg[B] < 4){
        changeDeg(A, +1);
        changeDeg(B, +1);
    }
    if((deg[A]== 3 || deg[B]==3)){

        if(deg[A] != 3){
        swap(A, B);
        }
        updInteresting(A, true);
        if(deg[B] == 3){
            updInteresting(B, true);
        }
    }

    if(isInteresting[A] || isInteresting[B]){

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

    if((deg[A] == 4 || deg[B]== 4) && above4 == 1){
        if(deg[A] != 4){
            swap(A, B);
        }
        updInteresting(A, false);
        if(deg[B] == 4){
            updInteresting(B, false);
        } 
        recalcDeg();
    }
}

int prev_res=  0;

int calc(){
  if(interesting.size() == 0){
    return 0;
  }
  else{
    if(above4 == 1){
        if((oc[0])*2 + oc[1] == (boringDSU.nbGroups-1)*2 && above3 ==1){
            return 1;
        }
        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);
        }
      }
      boringDSU.op_buffer.clear();

      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){
                  boringDSU.merge(e, iAdd);
                  if(!isInteresting[e]){
                    changeDeg(e, 1);
                  }
                  changeDeg(iAdd, 1);
                }
              }
            }
          }


          
          if((oc[0]-1)*2 + oc[1] == (boringDSU.nbGroups-1)*2 && above3 ==0){
            res++;
            //cerr<<iRem<<endl;
          }
          else{
            //cerr<<oc[0]<<" "<<oc[1]<<" "<<oc[2]<<endl;
          }


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


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

int CountCritical() {
  //cerr<<oc[0]<<" "<<oc[1]<<" "<<oc[2]<<" "<<oc[3]<<endl;
  prev_res = calc();
  return prev_res;

}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3420 KB Output is correct
2 Correct 3 ms 3164 KB Output is correct
3 Correct 4 ms 3160 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 3 ms 2908 KB Output is correct
6 Correct 3 ms 3164 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 3 ms 3164 KB Output is correct
9 Correct 4 ms 3416 KB Output is correct
10 Correct 4 ms 3416 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Runtime error 4 ms 7004 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3420 KB Output is correct
2 Correct 3 ms 3164 KB Output is correct
3 Correct 4 ms 3160 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 3 ms 2908 KB Output is correct
6 Correct 3 ms 3164 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 3 ms 3164 KB Output is correct
9 Correct 4 ms 3416 KB Output is correct
10 Correct 4 ms 3416 KB Output is correct
11 Correct 4 ms 3420 KB Output is correct
12 Correct 6 ms 4488 KB Output is correct
13 Correct 7 ms 3992 KB Output is correct
14 Correct 131 ms 3932 KB Output is correct
15 Correct 340 ms 4696 KB Output is correct
16 Correct 5 ms 3672 KB Output is correct
17 Correct 3 ms 3420 KB Output is correct
18 Correct 4 ms 3932 KB Output is correct
19 Correct 4 ms 3676 KB Output is correct
20 Correct 5 ms 4172 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3420 KB Output is correct
2 Correct 3 ms 3164 KB Output is correct
3 Correct 4 ms 3160 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 3 ms 2908 KB Output is correct
6 Correct 3 ms 3164 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 3 ms 3164 KB Output is correct
9 Correct 4 ms 3416 KB Output is correct
10 Correct 4 ms 3416 KB Output is correct
11 Correct 4 ms 3420 KB Output is correct
12 Correct 6 ms 4488 KB Output is correct
13 Correct 7 ms 3992 KB Output is correct
14 Correct 131 ms 3932 KB Output is correct
15 Correct 340 ms 4696 KB Output is correct
16 Correct 5 ms 3672 KB Output is correct
17 Correct 3 ms 3420 KB Output is correct
18 Correct 4 ms 3932 KB Output is correct
19 Correct 4 ms 3676 KB Output is correct
20 Correct 5 ms 4172 KB Output is correct
21 Correct 15 ms 7532 KB Output is correct
22 Correct 23 ms 9568 KB Output is correct
23 Correct 28 ms 11728 KB Output is correct
24 Execution timed out 4059 ms 9424 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3420 KB Output is correct
2 Correct 3 ms 3164 KB Output is correct
3 Correct 4 ms 3160 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 3 ms 2908 KB Output is correct
6 Correct 3 ms 3164 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 3 ms 3164 KB Output is correct
9 Correct 4 ms 3416 KB Output is correct
10 Correct 4 ms 3416 KB Output is correct
11 Runtime error 4 ms 7004 KB Execution killed with signal 11
12 Halted 0 ms 0 KB -