oj.uz

Submission #579612

# Submission time Handle Problem Language Result Execution time Memory
579612 2022-06-19T13:33:19 Z Josia Event Hopping (BOI22_events) C++17
25 / 100
 1500 ms 13604 KB 
#include <bits/stdc++.h>

using namespace std;

#define int int64_t



struct seg {
    vector<pair<int, int>> tree;

    seg(int n) {
        tree.assign(n*4, {1e18, -1});
    }

    void update(int v, int rl, int rr, int pos, pair<int, int> x) {
        if (rl == rr) {
            tree[v] = x;
            return;
        }
        int rm = (rl + rr) / 2;

        if (pos <= rm) update(v*2, rl, rm, pos, x);
        else update(v*2+1, rm+1, rr, pos, x);

        tree[v] = min(tree[v*2], tree[v*2+1]);
    }

    pair<int, int> query(int v, int rl, int rr, int ql, int qr) {
        if (ql > qr) return {1e18, -1};
        if (rl == ql && rr == qr) return tree[v];

        int rm = (rl + rr) / 2;

        return min(query(v*2, rl, rm, ql, min(rm, qr)), query(v*2+1, rm+1, rr, max(rm+1, ql), qr));
    }
};




signed main() {
    cin.tie(0);
    ios_base::sync_with_stdio(0);

    int n, q; cin >> n >> q;

    vector<tuple<int, int, int>> events(n);

    for (int i = 0; i<n; i++) {
        cin >> get<1>(events[i]) >> get<0>(events[i]);
        get<2>(events[i]) = i;    
    }

    sort(events.begin(), events.end());

    vector<pair<int, int>> segtreeRanges;

    for (auto i: events) {
        int l = upper_bound(events.begin(), events.end(), tuple<int, int, int>{get<1>(i)-1, 1e18, 1e18}) - events.begin();
        int r = upper_bound(events.begin(), events.end(), tuple<int, int, int>{get<0>(i), 1e18, 1e18}) - events.begin() - 1;
        segtreeRanges.push_back({l, r});
    }

    for (auto &i: events) swap(get<0>(i), get<1>(i));


    seg tree(n);

    for (int i = 0; i<n; i++) {
        tree.update(1, 0, n-1, i, {get<0>(events[i]), get<2>(events[i])});
    }


    vector<pair<int, int>> parents(n);

    for (int i = 0; i<n; i++) {
        parents[get<2>(events[i])] = tree.query(1, 0, n-1, segtreeRanges[i].first, segtreeRanges[i].second);
    }


    // for (auto i: parents) {
    //     cerr << i.first << " " << i.second << "\n";
    // }


    for (auto &i: events) swap(get<0>(i), get<2>(i));
    sort(events.begin(), events.end());
    for (auto &i: events) swap(get<0>(i), get<2>(i));

    // for (auto i: events) cerr << get<0>(i) << " " << get<1>(i) << "\n";


    for (int i = 0; i<q; i++) {
        int s, e; cin >> s >> e;
        s--;
        e--;
        // cerr << s << " " << e << "\n";

        if (s == e) {cout << 0 << "\n"; continue;}

        int cnt = 1;

        while (parents[e].second != e) {
            if (get<0>(events[e]) <= get<1>(events[s]) && get<1>(events[s]) <= get<1>(events[e])) {cout << cnt << "\n"; break;}

            e = parents[e].second;
            cnt++;

            if (get<0>(events[e]) <= get<1>(events[s]) && get<1>(events[s]) <= get<1>(events[e])) {cout << cnt << "\n"; break;}
        }
        if (!(get<0>(events[e]) <= get<1>(events[s]) && get<1>(events[s]) <= get<1>(events[e]))) cout << "impossible\n";
    }

    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Execution timed out 1600 ms 12076 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 2 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 3 ms 412 KB Output is correct
9 Correct 1 ms 340 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 2 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 3 ms 412 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 2 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 2 ms 340 KB Output is correct
17 Correct 2 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 790 ms 1452 KB Output is correct
20 Execution timed out 1582 ms 1284 KB Time limit exceeded
21 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 2 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 3 ms 412 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 2 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 2 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 235 ms 13604 KB Output is correct
20 Correct 129 ms 12264 KB Output is correct
21 Correct 122 ms 12192 KB Output is correct
22 Correct 93 ms 12192 KB Output is correct
23 Correct 73 ms 12396 KB Output is correct
24 Correct 87 ms 12212 KB Output is correct
25 Correct 55 ms 12168 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1591 ms 12188 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Execution timed out 1600 ms 12076 KB Time limit exceeded
3 Halted 0 ms 0 KB -