Submission #963596

#	Time	Username	Problem	Language	Result	Execution time	Memory
963596		Trisanu_Das	Garden (JOI23_garden)	C++17	100 / 100	2250 ms	8624 KiB

garden

#include <bits/stdc++.h>
using namespace std;
 
#define vt vector
#define size(x) (int((x).size()))
#define all(x) begin(x), end(x)
 
#define REP(a,b,c,d) for(int a=(b);(d)>0?a<=(c):a>=(c);a+=(d))
#define FOR(a,b,c) REP(a,b,c,1)
#define ROF(a,b,c) REP(a,b,c,-1)
 
struct DSU {
  vector<int> uf;
  DSU(int n):uf(vector<int>(n,-1)){}
  int find(int i){
    return uf[i]<0?i:uf[i]=find(uf[i]);
  }
  bool unite(int a,int b){
    if((a=find(a))==(b=find(b)))
      return false;
    if(uf[a]>uf[b])
      swap(a,b);
    uf[a]+=uf[b];
    uf[b]=a;
    return false;
  }
  int sz(int i){
    return -uf[find(i)];
  }
};
 
signed main() {
#ifndef DEBUG
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
#endif
  int N,M,D;
  cin>>N>>M>>D;
  vector<bool> x_need(D),y_need(D);
  for(int i = 0; i < N; i++){
    int x,y;
    cin>>x>>y;
    x_need[x]=y_need[y]=true;
  }
  vector<int> R(D,-1);
  vector<vector<int>> change(D);
  while(M--){
    int x,y;
    cin>>x>>y;
    if(!y_need[y]){
      R[y]=max(R[y],x);
      change[x].push_back(y);
    }
  }
  int ans=D*D;
  for(int l = 0; l < D; l++){
    vector<vector<int>> can_kill(D);
    vector<bool> deleted(D);
    DSU uf(D);
    int gap=0;
    auto insert=[&](int i){
      deleted[i]=true;
      for(int k:{-1,1}){
        int j=(i+k+D)%D;
        if(deleted[j]) uf.unite(i,j);
      }
      gap=max(gap,uf.sz(i));
    };
    for(int i = 0; i < D; i++){
      if (R[i]>=0) can_kill[R[i]].push_back(i);
      else if(!y_need[i]) insert(i);
    }
    int need=accumulate(all(x_need),0);
    for(int d = 1; d <= D; d++){
      int r=(l+d-1)%D;
      need-=x_need[r];
      for(int i:can_kill[r]) insert(i);
      if(!need) ans=min(ans,d*(D-gap));
    }
    for(int i:change[l]) R[i]=l;
  }
  cout<<ans<<'\n';
}

• Subtask 1: 15 / 15
• Subtask 2: 6 / 6
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 30 / 30
• Subtask 6: 25 / 25