Submission #415120

#	Time	Username	Problem	Language	Result	Execution time	Memory
415120		tengiz05	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	9 ms	1080 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using i64 = long long;
void solve(int n, int k, i64 A, int s) {
    std::vector<i64> a(n, -1);
    auto ask = [&](int i) -> i64 {
        if (~a[i]) {
            return a[i];
        } else {
            return a[i] = skim(i + 1);
        }
    };
    int l = -1, r = n;
    while (l + 1 < r) {
        int mid = (l + r) / 2;
        if (ask(mid) * k > A && ask(mid) * k < 2 * A) {
            l = mid;
            break;
        } else if (ask(mid) * k <= A) {
            l = mid;
        } else {
            r = mid;
        }
    }
    int t = std::max(0, l - k + 1);
    r = std::min(n - 1, l + k - 1);
    std::vector<int> ans;
    i64 sum = 0;
    for (; t + k - 1 <= r; t++) {
        ans.clear();
        sum = 0;
        for (int i = 0; i < k; i++) {
            sum += ask(i + t);
            ans.push_back(i + t + 1);
        }
        if (sum >= A && sum <= 2 * A) {
            answer(ans);
        }
        if (sum > 2 * A) {
            i64 sum = ask(t + k - 1);
            ans.clear();
            for (int i = 0; i < k - 1; i++) {
                sum += ask(i);
                ans.push_back(i + 1);
            }
            ans.push_back(t + k);
            if (sum >= A && sum <= 2 * A) {
                answer(ans);
            }
        }
    }
    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