Submission #540429

#	Time	Username	Problem	Language	Result	Execution time	Memory
540429		elazarkoren	A Difficult(y) Choice (BOI21_books)	C++17	0 / 100	2 ms	412 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] : 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 sum = 0;
    for (int i = 1; i <= k; i++) {
        sum += ask(i);
    }
    if (sum > 2 * a) {
        impossible();
        return;
    }
    vi ans;
    for (int i = 1; i < k; i++) {
        ans.push_back(i);
    }
    if (a <= sum) {
        ans.push_back(k);
        answer(ans);
        return;
    }
    sum -= ask(k);
    int begin = k + 1, end = n + 1, mid;
    while (begin < end) {
        mid = (begin + end) >> 1;
        ll x = ask(mid);
        if (a <= sum + x && x + sum <= 2 * a) {
            ans.push_back(mid);
            answer(ans);
            return;
        }
        if (a > sum + x) {
            begin = mid + 1;
        } else end = mid;
    }
    impossible();
}
//15 3 42 8

• 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