oj.uz

Submission #590299

# Submission time Handle Problem Language Result Execution time Memory
590299 2022-07-05T19:05:32 Z Error42 Event Hopping 2 (JOI21_event2) C++17
0 / 100
 481 ms 20436 KB 
#include <algorithm>
#include <climits>
#include <cmath>
#include <iostream>
#include <optional>
#include <set>
#include <vector>

using namespace std;

using ll = long long;

#define int ll

struct range {
    ll l, r;
};

struct event {
    int id;
    ::range range;

    event() : id(-1), range{ -1, -1 } {}
    event(int id, ::range range) : id(id), range(range) {}
};

struct started_range {
    ll r;
    event start;

    ::range range() const {
        return { start.range.r, r };
    }

    explicit started_range(ll r) : r(r), start(-1, ::range{ -INT_MAX, -INT_MAX }) {}
    started_range(ll r, const event& start) : r(r), start(start) {}

    bool operator <(const started_range& other) const {
        return r < other.r;
    }
};

int sqrt_n;
vector<event> events;
event first;
vector<optional<event>> next_one;
vector<optional<event>> next_sqrt_n;

int max_events(const started_range& sr) {
    ll r = sr.r;
    const int after_id = sr.start.id;

    int ans = 0;

    int cur = after_id;

    if (cur == -1) {
        ans++;
        cur = first.id;
    }

    while (next_sqrt_n[cur] && next_sqrt_n[cur]->range.r <= r) {
        ans += sqrt_n;
        cur = next_sqrt_n[cur]->id;
    }

    while (next_one[cur] && next_one[cur]->range.r <= r) {
        ans++;
        cur = next_one[cur]->id;
    }

    return ans;
}

signed main() {
    int n, k;
    cin >> n >> k;

    events.resize(n);

    for (int i = 0; i < n; i++) {
        event& e = events[i];
        e.id = i;
        cin >> e.range.l >> e.range.r;
    }

    next_one.resize(n);

    {
        vector<event> l_rev_sorted = events;
        sort(l_rev_sorted.begin(), l_rev_sorted.end(), [](const event& a, const event& b) {
            return a.range.l > b.range.l;
            });

        vector<event> r_rev_sorted = events;
        sort(r_rev_sorted.begin(), r_rev_sorted.end(), [](const event& a, const event& b) {
            return a.range.r > b.range.r;
            });

        int r_min = -1;
        int l_idx = 0;

        for (const event& cur : r_rev_sorted) {
            while (l_idx < l_rev_sorted.size()
                && l_rev_sorted[l_idx].range.l >= cur.range.r) {

                if (r_min == - 1 || l_rev_sorted[l_idx].range.r < events[r_min].range.r)
                    r_min = l_rev_sorted[l_idx].id;
                l_idx++;
            }

            if (r_min != -1)
                next_one[cur.id] = events[r_min];
        }

        first = r_rev_sorted.back();
    }

    // does not need to be exact
    sqrt_n = int(sqrt(double(n)));

    next_sqrt_n.resize(n);

    for (int i = 0; i < n; i++) {
        int cur = i;

        for (int j = 0; j < sqrt_n && cur != -1; j++) {
            if (next_one[cur])
                cur = next_one[cur]->id;
            else
                cur = -1;
        }

        if (cur != -1)
            next_sqrt_n[i] = events[cur];
    }

    set<started_range> usable = { started_range(INT_MAX) };

    int cur_events = max_events(*usable.begin());

    if (cur_events < k) {
        cout << "-1\n";
        return 0;
    }

    vector<bool> in(n, false);

    for (const auto& tested : events) {
        auto usable_it = usable.lower_bound(started_range(tested.range.r));

        if (usable_it->range().l > tested.range.l)
            continue;

        int before_split = max_events(*usable_it);

        started_range split_l = *usable_it;
        split_l.r = tested.range.l;

        started_range split_r{ usable_it->r, tested };

        int after_split = max_events(split_l) + 1 + max_events(split_r);

        if (cur_events - before_split + after_split >= k) {
            in[tested.id] = true;

            usable.erase(*usable_it);
            usable.insert(split_l);
            usable.insert(split_r);
        }
    }

    vector<int> solution;

    for (int i = 0; solution.size() < k; i++)
        if (in[i])
            solution.push_back(i);

    for (const int x : solution)
        cout << x + 1 << "\n";
}

Compilation message

event2.cpp: In function 'int main()':
event2.cpp:104:26: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<event>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |             while (l_idx < l_rev_sorted.size()
      |                    ~~~~~~^~~~~~~~~~~~~~~~~~~~~
event2.cpp:175:37: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
  175 |     for (int i = 0; solution.size() < k; i++)
      |                     ~~~~~~~~~~~~~~~~^~~

Subtask #1
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 304 KB Output is correct
4 Correct 479 ms 20436 KB Output is correct
5 Correct 476 ms 20356 KB Output is correct
6 Correct 475 ms 20288 KB Output is correct
7 Correct 480 ms 20064 KB Output is correct
8 Correct 479 ms 20320 KB Output is correct
9 Correct 460 ms 20340 KB Output is correct
10 Correct 481 ms 20196 KB Output is correct
11 Correct 455 ms 20336 KB Output is correct
12 Correct 321 ms 16652 KB Output is correct
13 Correct 303 ms 16596 KB Output is correct
14 Correct 324 ms 16508 KB Output is correct
15 Correct 318 ms 16512 KB Output is correct
16 Correct 260 ms 12352 KB Output is correct
17 Correct 257 ms 12356 KB Output is correct
18 Correct 257 ms 12504 KB Output is correct
19 Correct 223 ms 12356 KB Output is correct
20 Incorrect 222 ms 12400 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #2
0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Incorrect 1 ms 300 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Incorrect 1 ms 300 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #4
0 / 61.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 304 KB Output is correct
4 Correct 479 ms 20436 KB Output is correct
5 Correct 476 ms 20356 KB Output is correct
6 Correct 475 ms 20288 KB Output is correct
7 Correct 480 ms 20064 KB Output is correct
8 Correct 479 ms 20320 KB Output is correct
9 Correct 460 ms 20340 KB Output is correct
10 Correct 481 ms 20196 KB Output is correct
11 Correct 455 ms 20336 KB Output is correct
12 Correct 321 ms 16652 KB Output is correct
13 Correct 303 ms 16596 KB Output is correct
14 Correct 324 ms 16508 KB Output is correct
15 Correct 318 ms 16512 KB Output is correct
16 Correct 260 ms 12352 KB Output is correct
17 Correct 257 ms 12356 KB Output is correct
18 Correct 257 ms 12504 KB Output is correct
19 Correct 223 ms 12356 KB Output is correct
20 Incorrect 222 ms 12400 KB Output isn't correct
21 Halted 0 ms 0 KB -