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Submission #634377

# Submission time Handle Problem Language Result Execution time Memory
634377 2022-08-24T10:21:51 Z dooompy Event Hopping (BOI22_events) C++17
25 / 100
 423 ms 14896 KB 
#include <bits/stdc++.h>

using namespace std;

int s[100005], e[100005];

vector<int> comp;

pair<int, int> tree[4 * 100005];

void update(int x, int l, int r, int loc, pair<int, int> stuff) {
    if (l == r) {
        tree[x] = min(tree[x], stuff);
        return;
    }

    int mid = (l + r) / 2;

    if (loc <= mid) update(2 * x, l, mid, loc, stuff);
    else update(2 * x + 1, mid + 1, r, loc, stuff);

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

int convert(int x) {
    return lower_bound(comp.begin(), comp.end(), x) - comp.begin() + 1;
}

int prevjmp[100005][20];

pair<int, int> get(int x, int l, int r, int ql, int qr) {
    if (ql <= l && r <= qr) return tree[x];
    if (l > qr || r < ql) return {1e9, 1e9};

    int mid = (l + r) / 2;

    return min(get(2 * x, l, mid, ql, qr), get(2 * x + 1, mid + 1, r, ql, qr));
}

int main() {
    int n, q; cin >> n >> q;
    for (int i = 1; i <= n; i++) {
        cin >> s[i] >> e[i];
        comp.push_back(s[i]);
        comp.push_back(e[i]);
    }

    fill(&tree[0], &tree[0] + sizeof(tree) / sizeof(tree[0]), make_pair(1e9, 1e9));

    sort(comp.begin(), comp.end());
    comp.resize(unique(comp.begin(), comp.end()) - comp.begin());

    int sz = comp.size();

    for (int i = 1; i <= n; i++) {
        // find furtherst cano back
        s[i] = convert(s[i]);
        e[i] = convert(e[i]);

        update(1, 1, sz, e[i], {s[i], i});
    }

    for (int i = 1; i <= n; i++) {
        prevjmp[i][0] = get(1, 1, sz, s[i], e[i]).second;
    }

    for (int log = 1; log < 20; log++) {
        for (int i = 1; i <= n; i++) {
            prevjmp[i][log] = prevjmp[prevjmp[i][log-1]][log-1];
        }
    }


    for (int i = 0; i < q; i++) {
        long long ans = 0;
        int a, b; cin >> a >> b;

        if (a == b) {
            cout << "0\n";
            continue;
        }

        if (e[a] > e[b]) {
            cout << "impossible\n";
            continue;
        }

        if (s[b] <= e[a] && e[a] <= e[b]) {
            cout << "1\n";
            continue;
        }

        for (int log = 19; log >= 0; log--) {
            if (s[prevjmp[b][log]] > e[a]) {
                b = prevjmp[b][log];
                ans += (long long) (1 << log);
            }
        }

        b = prevjmp[b][0];

        if (s[b] > e[a]) {
            cout << "impossible\n";
            continue;
        } else {
            cout << ans + 2 << "\n";
        }
    }
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 331 ms 13744 KB Output is correct
3 Correct 377 ms 13544 KB Output is correct
4 Correct 395 ms 13448 KB Output is correct
5 Correct 355 ms 13572 KB Output is correct
6 Correct 423 ms 13588 KB Output is correct
7 Correct 397 ms 13648 KB Output is correct
8 Runtime error 93 ms 10152 KB Execution killed with signal 11
9 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 4 ms 3540 KB Output is correct
4 Correct 3 ms 3540 KB Output is correct
5 Correct 3 ms 3540 KB Output is correct
6 Correct 3 ms 3540 KB Output is correct
7 Correct 4 ms 3540 KB Output is correct
8 Correct 3 ms 3524 KB Output is correct
9 Correct 3 ms 3540 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 4 ms 3540 KB Output is correct
4 Correct 3 ms 3540 KB Output is correct
5 Correct 3 ms 3540 KB Output is correct
6 Correct 3 ms 3540 KB Output is correct
7 Correct 4 ms 3540 KB Output is correct
8 Correct 3 ms 3524 KB Output is correct
9 Correct 3 ms 3540 KB Output is correct
10 Correct 2 ms 3412 KB Output is correct
11 Correct 2 ms 3412 KB Output is correct
12 Correct 3 ms 3540 KB Output is correct
13 Correct 3 ms 3540 KB Output is correct
14 Correct 3 ms 3540 KB Output is correct
15 Correct 5 ms 3524 KB Output is correct
16 Correct 4 ms 3540 KB Output is correct
17 Correct 4 ms 3540 KB Output is correct
18 Correct 3 ms 3524 KB Output is correct
19 Correct 184 ms 5436 KB Output is correct
20 Correct 181 ms 5504 KB Output is correct
21 Correct 184 ms 5692 KB Output is correct
22 Correct 187 ms 5812 KB Output is correct
23 Correct 180 ms 5612 KB Output is correct
24 Correct 202 ms 5548 KB Output is correct
25 Correct 180 ms 5276 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 4 ms 3540 KB Output is correct
4 Correct 3 ms 3540 KB Output is correct
5 Correct 3 ms 3540 KB Output is correct
6 Correct 3 ms 3540 KB Output is correct
7 Correct 4 ms 3540 KB Output is correct
8 Correct 3 ms 3524 KB Output is correct
9 Correct 3 ms 3540 KB Output is correct
10 Correct 3 ms 3412 KB Output is correct
11 Correct 2 ms 3412 KB Output is correct
12 Correct 3 ms 3540 KB Output is correct
13 Correct 4 ms 3540 KB Output is correct
14 Correct 3 ms 3540 KB Output is correct
15 Correct 4 ms 3524 KB Output is correct
16 Correct 3 ms 3524 KB Output is correct
17 Correct 3 ms 3540 KB Output is correct
18 Correct 2 ms 3540 KB Output is correct
19 Correct 173 ms 14896 KB Output is correct
20 Correct 139 ms 14048 KB Output is correct
21 Correct 167 ms 14804 KB Output is correct
22 Runtime error 117 ms 12144 KB Execution killed with signal 11
23 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 368 ms 13444 KB Output is correct
2 Correct 366 ms 13480 KB Output is correct
3 Correct 410 ms 13504 KB Output is correct
4 Runtime error 98 ms 10092 KB Execution killed with signal 11
5 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 331 ms 13744 KB Output is correct
3 Correct 377 ms 13544 KB Output is correct
4 Correct 395 ms 13448 KB Output is correct
5 Correct 355 ms 13572 KB Output is correct
6 Correct 423 ms 13588 KB Output is correct
7 Correct 397 ms 13648 KB Output is correct
8 Runtime error 93 ms 10152 KB Execution killed with signal 11
9 Halted 0 ms 0 KB -