Submission #783638

#	Time	Username	Problem	Language	Result	Execution time	Memory
783638		Hanksburger	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	1 ms	300 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> ans;
void solve(int n, int k, long long a, int s)
{
    long long x[11]={}, y[11]={}, l=1, r=n+1;
    while (l<r)
    {
        int m=(l+r)/2;
        if (skim(m)>=a)
            r=m;
        else
            l=m+1;
    }
    for (int i=1; i<=k; i++)
        x[i]=x[i-1]+skim(i);
    if (l>=k && l<=n)
    {
        if (x[k-1]+skim(l)<=a*2)
        {
            for (int i=1; i<k; i++)
                ans.push_back(i);
            ans.push_back(l);
            answer(ans);
            return;
        }
    }
    if (l>k)
    {
        for (int i=1; i<=k; i++)
            y[i]=y[i-1]+skim(l-i);
        for (int i=0; i<=k; i++)
        {
            if (x[k-i]+y[i]>=a && x[k-i]+y[i]<=a*2)
            {
                for (int j=1; j<=k-i; j++)
                    ans.push_back(j);
                for (int j=l-i; j<l; j++)
                    ans.push_back(j);
                answer(ans);
                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