Submission #1334350

#	Time	Username	Problem	Language	Result	Execution time	Memory
1334350		enson	A Difficult(y) Choice (BOI21_books)	C++20	100 / 100	1 ms	1180 KiB

books

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

void solve(int N, int K, long long A, int S){
    int l = 0, r = N;
    int m = (l+r)/2;
    vector<long long>F(N, -1);
    while (l < r){
        m = (l+r)/2;
        F[m] = skim(m+1);
        if (F[m] >= A){
            r = m;
        } else {
            l = m+1;
        }
    }
    if (l < K-1) impossible();
    long long ans = 0;
    if (l != N){
        F[l] = skim(l+1);
        for(int i = 1; i < K; i++){
            if (F[i-1] == -1) F[i-1] = skim(i);
            ans += F[i-1];
        }
        ans += F[l];
        if (ans <= 2*A){
            vector<int>v;
            for(int i = 1; i < K; i++)v.push_back(i);
            v.push_back(l+1);
            answer(v);
        }
    }
    if (l < K) impossible();
    for(int i = 0; i <= K; i++){
        vector<int>v;
        ans = 0;
        for(int j = 0; j < K-i; j++){
            if (F[j] == -1)F[j] = skim(j+1);
            ans += F[j];
            v.push_back(j+1);
        }
        for(int j = l-1; j >= l-i; j--){
            if (F[j] == -1)F[j] = skim(j+1);
            ans += F[j];
            v.push_back(j+1);
        }
        if (ans >= A && ans <= 2*A) answer(v);
    }
    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