Submission #1101391

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101391		MateiKing80	A Difficult(y) Choice (BOI21_books)	C++14	100 / 100	2 ms	1276 KiB

books

#include <bits/stdc++.h>
#include "books.h"

using namespace std;

typedef long long ll;

void solve(int N, int K, long long A, int S)
{
    vector<ll> x(N + 1);
    ll sum = 0;
    for(int i = 1; i <= K; i ++)
        sum += x[i] = skim(i);
    if(sum > 2 * A)
        impossible();
    sum -= x[K];
    int l = K + 1, h = N, a = N + 1;
    while(l <= h)
    {
        int mid = (l + h) / 2;
        if(skim(mid) >= A)
        {
            h = mid - 1;
            a = mid;
        }
        else
            l = mid + 1;
    }
    if(a != N + 1)
    {
        sum += x[a] = skim(a);
        if(sum <= 2 * A)
        {
            vector<int> ans;
            for(int i = 1; i < K; i ++)
                ans.push_back(i);
            ans.push_back(a);
            answer(ans);
            return;
        }
    }
    for(int i = 0; i < K; i ++)
        x[a - i - 1] = skim(a - i - 1);
    for(int i = 0; i <= K; i ++)
    {
        sum = 0;
        vector<int> ans;
        for(int j = 1; j <= K - i; j ++)
        {
            sum += x[j];
            ans.push_back(j);
        }
        for(int j = 0; j < i; j ++)
        {
            sum += x[a - j - 1];
            ans.push_back(a - j - 1);
        }
        if(sum >= A && sum <= 2 * A)
        {
            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