Submission #906276

#	Time	Username	Problem	Language	Result	Execution time	Memory
906276		Ahmed57	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	2 ms	1404 KiB

books

#include "books.h"
#include <bits/stdc++.h>
 
using namespace std;
 
void solve(int n,int k,long long a,int s){
    int l = 1 , r = n , ans = n+1;
    while(l<=r){
        int mid = (l+r)/2;
        if(skim(mid)>a){
            ans = mid;
            r = mid-1;
        }else l = mid+1;
    }
    long long arr[k+1];
    long long las[n+1];
    long long all = 0;
    for(int i= 1;i<=k;i++){
        arr[i] = skim(i);
        if(i<k){
            all+=arr[i];
        }
    }
    for(int i = min(ans,n);i>=max(1,ans-k);i--){
        las[i] = skim(i);
    }
    if(ans<=n&&all+las[ans]>=a&&all+las[ans]<=2*a&&k-1+(ans>=k)==k){
        vector<int> an;
        for(int i = 1;i<k;i++)an.push_back(i);
        an.push_back(ans);
        answer(an);return ;
    }
    all = 0;
    for(int i = 0;i<=k;i++){
        if(i)all+=arr[k-i+1];
        long long extra = 0 , cnt = 0;
        for(int j = max((i?k+1:1),ans-k);j<min(ans,max((i?k+1:1),ans-k)+(k-i));j++){
            extra+=las[j];
            cnt++;
        }
        if(all+extra>=a&&all+extra<=2*a&&cnt+i==k){
            vector<int> an;
            for(int j = k;j>=k-i+1;j--)an.push_back(j);
            for(int j = max((i?k+1:1),ans-k);j<max((i?k+1:1),ans-k)+(k-i);j++)an.push_back(j);
            answer(an);return ;
        }
    }
    impossible();
}

• 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