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Submission #1020232

# Submission time Handle Problem Language Result Execution time Memory
1020232 2024-07-11T17:49:38 Z anton Parachute rings (IOI12_rings) C++17
38 / 100
 4000 ms 262144 KB 
#include<bits/stdc++.h>

using namespace std;




struct DSU{
  int nbGroups =0;
  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){
    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];
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);
}

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 11 ms 24156 KB Output is correct
2 Correct 13 ms 25256 KB Output is correct
3 Correct 14 ms 25376 KB Output is correct
4 Correct 11 ms 24412 KB Output is correct
5 Correct 12 ms 24924 KB Output is correct
6 Correct 12 ms 25272 KB Output is correct
7 Correct 11 ms 24668 KB Output is correct
8 Correct 11 ms 25296 KB Output is correct
9 Correct 13 ms 25436 KB Output is correct
10 Correct 13 ms 25464 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 315 ms 121360 KB Output is correct
2 Correct 1139 ms 186264 KB Output is correct
3 Correct 219 ms 104496 KB Output is correct
4 Correct 748 ms 232552 KB Output is correct
5 Correct 726 ms 232592 KB Output is correct
6 Correct 701 ms 231056 KB Output is correct
7 Correct 208 ms 104432 KB Output is correct
8 Runtime error 769 ms 262144 KB Execution killed with signal 9
9 Halted 0 ms 0 KB -

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 24156 KB Output is correct
2 Correct 13 ms 25256 KB Output is correct
3 Correct 14 ms 25376 KB Output is correct
4 Correct 11 ms 24412 KB Output is correct
5 Correct 12 ms 24924 KB Output is correct
6 Correct 12 ms 25272 KB Output is correct
7 Correct 11 ms 24668 KB Output is correct
8 Correct 11 ms 25296 KB Output is correct
9 Correct 13 ms 25436 KB Output is correct
10 Correct 13 ms 25464 KB Output is correct
11 Correct 12 ms 25412 KB Output is correct
12 Correct 18 ms 26888 KB Output is correct
13 Correct 14 ms 26588 KB Output is correct
14 Correct 140 ms 25436 KB Output is correct
15 Correct 392 ms 26000 KB Output is correct
16 Correct 13 ms 25996 KB Output is correct
17 Correct 12 ms 25180 KB Output is correct
18 Correct 13 ms 25692 KB Output is correct
19 Correct 14 ms 26008 KB Output is correct
20 Correct 14 ms 26568 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 24156 KB Output is correct
2 Correct 13 ms 25256 KB Output is correct
3 Correct 14 ms 25376 KB Output is correct
4 Correct 11 ms 24412 KB Output is correct
5 Correct 12 ms 24924 KB Output is correct
6 Correct 12 ms 25272 KB Output is correct
7 Correct 11 ms 24668 KB Output is correct
8 Correct 11 ms 25296 KB Output is correct
9 Correct 13 ms 25436 KB Output is correct
10 Correct 13 ms 25464 KB Output is correct
11 Correct 12 ms 25412 KB Output is correct
12 Correct 18 ms 26888 KB Output is correct
13 Correct 14 ms 26588 KB Output is correct
14 Correct 140 ms 25436 KB Output is correct
15 Correct 392 ms 26000 KB Output is correct
16 Correct 13 ms 25996 KB Output is correct
17 Correct 12 ms 25180 KB Output is correct
18 Correct 13 ms 25692 KB Output is correct
19 Correct 14 ms 26008 KB Output is correct
20 Correct 14 ms 26568 KB Output is correct
21 Correct 25 ms 30684 KB Output is correct
22 Correct 36 ms 34124 KB Output is correct
23 Correct 40 ms 37040 KB Output is correct
24 Execution timed out 4072 ms 32868 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 24156 KB Output is correct
2 Correct 13 ms 25256 KB Output is correct
3 Correct 14 ms 25376 KB Output is correct
4 Correct 11 ms 24412 KB Output is correct
5 Correct 12 ms 24924 KB Output is correct
6 Correct 12 ms 25272 KB Output is correct
7 Correct 11 ms 24668 KB Output is correct
8 Correct 11 ms 25296 KB Output is correct
9 Correct 13 ms 25436 KB Output is correct
10 Correct 13 ms 25464 KB Output is correct
11 Correct 315 ms 121360 KB Output is correct
12 Correct 1139 ms 186264 KB Output is correct
13 Correct 219 ms 104496 KB Output is correct
14 Correct 748 ms 232552 KB Output is correct
15 Correct 726 ms 232592 KB Output is correct
16 Correct 701 ms 231056 KB Output is correct
17 Correct 208 ms 104432 KB Output is correct
18 Runtime error 769 ms 262144 KB Execution killed with signal 9
19 Halted 0 ms 0 KB -