Submission #900996

#	Time	Username	Problem	Language	Result	Execution time	Memory
900996		simona1230	A Difficult(y) Choice (BOI21_books)	C++17	60 / 100	132 ms	1484 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using namespace std;

long long n,k,a,s;
long long x[120001];

void know_all()
{
    for(long long i=1; i<=n; i++)
    {
        x[i]=skim(i);
    }

    long long fk=0,fs=0,fsidx=0;
    for(int i=1; i<=n; i++)
    {
        if(i<k)fk+=x[i];
        if(x[i]>=a)
        {
            fs=x[i];
            fsidx=i;
            break;
        }
    }

    if(fs+fk>=a&&fs+fk<=2*a)
    {
        vector<int> ans;
        for(int i=1; i<k; i++)
            ans.push_back(i);
        ans.push_back(fsidx);
        answer(ans);
        return;
    }

    long long sum=0;
    for(int i=1; i<=n; i++)
    {
        sum+=x[i];
        if(i>k)sum-=x[i-k];
        if(i>=k&&sum>=a&&sum<=2*a)
        {
            vector<int> ans;
            for(int j=i-k+1; j<=i; j++)
                ans.push_back(j);
            answer(ans);
            return;
        }
    }

    impossible();
}

long long val(int idx)
{
    if(x[idx]==0)x[idx]=skim(idx);
    return x[idx];
}

void solve(int N,int K,long long A,int S)
{
    n=N;
    k=K;
    a=A;
    s=S;

    if(s==n)
    {
        know_all();
        return;
    }

    int lidx=1,ridx=n,idx=0;
    while(lidx<=ridx)
    {
        int m=(lidx+ridx)/2;
        if(val(m)>=a)
        {
            idx=m;
            ridx=m-1;
        }
        else lidx=m+1;
    }

    if(idx!=0)
    {
        long long fk=0;
        for(int i=1; i<k; i++)
            fk+=val(i);

        if(fk+val(idx)>=a&&fk+val(idx)<=2*a)
        {
            vector<int> ans;
            for(int i=1; i<k; i++)
                ans.push_back(i);
            ans.push_back(idx);
            answer(ans);
            return;
        }
    }


    int l=1,r=n-k+1;
    while(l<=r)
    {
        int m=(l+r)/2;
        long long sum=0;
        for(int i=m; i<=m+k-1; i++)
            sum+=val(i);
        if(sum>=a&&sum<=2*a)
        {
            vector<int> ans;
            for(int i=m; i<=m+k-1; i++)
                ans.push_back(i);
            answer(ans);
            return;
        }
        if(sum<a)l=m+1;
        else r=m-1;
    }
    impossible();
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20