Submission #1128889

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128889		test00	A Difficult(y) Choice (BOI21_books)	C++20	100 / 100	0 ms	412 KiB

books

#include "bits/stdc++.h"
#include "books.h"
//#define int long long
using namespace std;
#define all(v) v.begin(),v.end()
#define sz(v) (int)v.size()

map<int,long long> Cache;
int S;
long long ask(int ind){
  if(Cache.count(ind)) return Cache[ind];
  Cache[ind]=skim(ind);
  assert(sz(Cache)<=S);
  return Cache[ind];
}

void solve(int n, int k, long long A, int s) {
	S=s;
    vector<long long> ilk;
    for(int i=1;i<=k;i++) ilk.push_back(ask(i));
    long long summ=accumulate(all(ilk),0LL);
    if(summ>2*A){
      impossible();
      return;
    }
    if(summ>=A){
      vector<int> lol;
      for(int i=1;i<=k;i++) lol.push_back(i);
      answer(lol);
      return;
    }
    int l=k,r=n,idx=n+1;
    while(l<=r){
      int mid=(l+r)/2;
      if(ask(mid)<A) l=mid+1;
      else {
        r=mid-1;
        idx=mid;
      }
    }
    l=idx-1;

    if(l+1<=n){
      long long res=ask(l+1);
      for(int i=0;i<k-1;i++) res+=ilk[i];
      if(res>=A && res<=2*A){
       vector<int> lol;
       for(int i=1;i<k;i++) lol.push_back(i);
       lol.push_back(l+1);
       answer(lol);
       return;
      }
    }
    
    for(int i=l;i>k;i--){
      summ-=ilk.back();
      ilk.pop_back();
      summ+=ask(i);
      if(summ>=A && summ<=2*A){
       vector<int> lol;
       for(int j=1;j<=sz(ilk);j++) lol.push_back(j);
       for(int j=i;j<=l;j++) lol.push_back(j);
       answer(lol);
       return;
      }
      if(ilk.empty()){
      	impossible();
        return;
      }
    }

    impossible();
    return;
}

/*
void _(){
  
}

int32_t main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  int tc=1;//cin >> tc;
  while(tc--) _();
}*/

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20