Submission #411562

#	Time	Username	Problem	Language	Result	Execution time	Memory
411562		Aldas25	A Difficult(y) Choice (BOI21_books)	C++14	100 / 100	4 ms	328 KiB

books

#include <bits/stdc++.h>

#include "books.h"

using namespace std;

#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr)
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define REP(n) FOR(O, 1, (n))
#define f first
#define s second
#define pb push_back
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
typedef vector<ll> vl;

const int MAXN = 1e5 + 100;

int n, k, s;
ll a;

unordered_map<int, ll> saved;

ll get (int i) {
    if (saved[i] > 0)return saved[i];
    saved[i] = skim(i);
    return saved[i];
}

void solve(int N, int K, long long A, int S) {
    n = N;
    k = K;
    a = A;
    s = S;

    vi ids;
    FOR(i, 1, k) {
        ids.pb(i);
    }

    //if (get() {
        int le = 1, ri = n;
        while (le < ri) {
            int mid = (le+ri)/2;
            if (get(mid) > a) ri = mid;
            else le = mid+1;
        }
        le = max(le, k);
        //if (get(le) <= a) le =
//cout << " le = " << le << endl;
        ll cur = 0;
        FOR(i, 1, k-1) cur += get(i);
        cur += get(le);

        if (a <= cur && cur <= 2*a) {
            vi ret;
            FOR(i, 1, k-1) ret.pb(i);
            ret.pb(le);
            answer(ret);
            return;
        }

        if (get(le) < a) le = n+1;
        FOR(i, max(k+1, le-k), le-1) ids.pb(i);
    //}

    FOR(i, 0, k) {
        ll cur = 0;
        vi ret;
        FOR(j, 0, i-1) {
            cur += get(ids[j]);
            ret.pb(ids[j]);
        }
        FOR(j, (int)ids.size()-(k-i), (int)ids.size()-1) {
            cur += get(ids[j]);
            ret.pb(ids[j]);
        }

        if (a <= cur && cur <= 2*a) {
            answer(ret);
            return;
        }
    }

    //answer(ret);
    impossible();
}


/*
15 3 27 40
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21


*/

• 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