Submission #540435

#	Time	Username	Problem	Language	Result	Execution time	Memory
540435		elazarkoren	A Difficult(y) Choice (BOI21_books)	C++17	0 / 100	1 ms	336 KiB

books

#include <bits/stdc++.h>
#include "books.h"
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
typedef vector<bool> vb;

const int MAX_N = 1005;

ll books[MAX_N];

ll ask(int i) {
    return books[i] = (books[i] ? books[i] : skim(i));
}

void solve(int n, int k, long long a, int s) {
//    for (int i = 1; i <= n; i++) {
//        books[i] = skim(i);
//    }
//    for (int i = 1; i <= n; i++) {
//        for (int l = i + 1, r = n; l < r;) {
//            ll sum = books[i] + books[l] + books[r];
//            if (a <= sum && sum <= 2 * a) {
//                answer({i, l, r});
//                return;
//            }
//            if (sum < a) l++;
//            else r--;
//        }
//    }
//    impossible();
//    ll sum2 = 0;
//    for (int i = n - k + 1; i <= n; i++) {
//        sum2 += ask(i);
//    }
//    if (sum2 < a) {
//        impossible();
//        return;
//    }
    ll sum = 0;
    vi l, r;
    for (int i = 1; i <= k; i++) {
        sum += ask(i);
        l.push_back(i);
    }
    if (sum > 2 * a) {
        impossible();
        return;
    }
    if (a <= sum) {
        answer(l);
        return;
    }
    for (int i = k; i; i--) {
        sum -= books[i];
        l.pop_back();
        ll x = ask(n - k + i);
        if (x + sum < a) {
            r.push_back(n - k + i);
            sum += x;
            continue;
        }
        int begin = k + 1, end = n - k + i + 1, mid;
        while (begin < end) {
            mid = (begin + end) >> 1;
            x = ask(mid);
            if (a <= sum + x && x + sum <= 2 * a) {
                r.push_back(mid);
                for (int j : r) l.push_back(j);
                answer(l);
                return;
            }
            if (a > sum + x) {
                begin = mid + 1;
            } else end = mid;
        }
        for (int j : r) l.push_back(j);
        answer(l);
        return;
    }
//    l.push_back(mid);
//    answer(l);
    impossible();
}
//6 3 20 6
//1 2 3 8 9 10

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