oj.uz

Submission #917154

# Submission time Handle Problem Language Result Execution time Memory
917154 2024-01-27T10:30:46 Z 406 Event Hopping (BOI22_events) C++17
25 / 100
 132 ms 159192 KB 
#include <bits/stdc++.h>
#define int int64_t
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)

using namespace std;
using ar = array<int, 2>;
using ar3 = array<int, 3>;

const int64_t INF = 1ll << 60;
const int N = 2e5 + 5;
const int LG = 20;

namespace RMQ {
        ar mn[LG][N];

        void build(ar a[], int n) {
                FOR(i, 0, n) mn[0][i] = a[i];

                FOR(l, 0, LG - 1) FOR(i, 0, n)
                        mn[l + 1][i] = min(mn[l][i], mn[l][i + (1 << l)]);
        }

        int get(int l, int r) { //[l, r)
                int t = __lg(r - l);
                return min(mn[t][l], mn[t][r - (1 << t)])[1];
        }
}

int pr[N][LG], h[N], D[2 * N], loc[N], n, q;
ar3 it[N];
ar en[2 * N];

signed main() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr); 
        cin >> n >> q;
        FOR(i, 0, n) {
                cin >> it[i][0] >> it[i][1];
                it[i][2] = i;
                D[i << 1] = it[i][0];
                D[i << 1 | 1] = it[i][1];
        }
        fill(en, en + 2 * n, ar{INF, INF});
        sort(D, D + 2 * n);
        sort(it, it + n, [](const auto &A, const auto &B) {
                if (A[0] != B[0]) return A[0] < B[0];
                return A[2] < B[2];
        });


        FOR(i, 0, n) {
                it[i][0] = lower_bound(D, D + 2 * n, it[i][0]) - D;
                it[i][1] = lower_bound(D, D + 2 * n, it[i][1]) - D;
                en[it[i][1]] = min(en[it[i][1]], ar{it[i][0], i});
                loc[it[i][2]] = i;
        }
        RMQ::build(en, 2 * n);

        FOR(i, 0, n) {
                pr[i][0] = i;
                auto [l, r, x] = it[i];
                int idx = RMQ::get(l, r + 1);
                assert(idx <= i);
                if (idx != i) {
                        h[i] = h[idx] + 1;
                        pr[i][0] = idx;
                        FOR(l, 0, LG - 1)
                                pr[i][l + 1] = pr[pr[i][l]][l];
                }
        }

        while (q--) {
                int s, e;
                cin >> s >> e;
                --s, --e;
                s = loc[s], e = loc[e];
                if (it[e][1] < it[s][0] || it[s][1] > it[e][1]) cout << "impossible\n";
                else if (s == e) cout << 0 << '\n';
                else if (it[s][1] < it[e][0]) {
                        int sr = it[s][1], v = e;

                        for (int i = LG - 1; i >= 0; --i) {
                                int l = it[pr[v][i]][0];
                                if (l > sr)
                                        v = pr[v][i];
                        }
                        v = pr[v][0];
                        if (it[v][0] > sr) cout << "impossible\n";
                        else cout << h[e] - h[v] + 1 << '\n';
                }
                else cout << "1\n";
        }

        return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 49496 KB Output is correct
2 Runtime error 126 ms 157324 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 49500 KB Output is correct
2 Correct 7 ms 49500 KB Output is correct
3 Correct 9 ms 49756 KB Output is correct
4 Correct 9 ms 49756 KB Output is correct
5 Correct 8 ms 49588 KB Output is correct
6 Correct 8 ms 49716 KB Output is correct
7 Correct 9 ms 50012 KB Output is correct
8 Correct 8 ms 49756 KB Output is correct
9 Correct 7 ms 49756 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 49500 KB Output is correct
2 Correct 7 ms 49500 KB Output is correct
3 Correct 9 ms 49756 KB Output is correct
4 Correct 9 ms 49756 KB Output is correct
5 Correct 8 ms 49588 KB Output is correct
6 Correct 8 ms 49716 KB Output is correct
7 Correct 9 ms 50012 KB Output is correct
8 Correct 8 ms 49756 KB Output is correct
9 Correct 7 ms 49756 KB Output is correct
10 Correct 8 ms 49496 KB Output is correct
11 Correct 7 ms 49500 KB Output is correct
12 Correct 9 ms 49648 KB Output is correct
13 Correct 8 ms 49752 KB Output is correct
14 Correct 8 ms 49756 KB Output is correct
15 Correct 8 ms 49756 KB Output is correct
16 Correct 8 ms 49756 KB Output is correct
17 Correct 8 ms 49756 KB Output is correct
18 Correct 7 ms 49756 KB Output is correct
19 Correct 39 ms 57676 KB Output is correct
20 Correct 40 ms 57424 KB Output is correct
21 Correct 37 ms 57588 KB Output is correct
22 Correct 32 ms 57760 KB Output is correct
23 Correct 31 ms 57592 KB Output is correct
24 Correct 29 ms 57680 KB Output is correct
25 Correct 40 ms 57248 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 49500 KB Output is correct
2 Correct 7 ms 49500 KB Output is correct
3 Correct 9 ms 49756 KB Output is correct
4 Correct 9 ms 49756 KB Output is correct
5 Correct 8 ms 49588 KB Output is correct
6 Correct 8 ms 49716 KB Output is correct
7 Correct 9 ms 50012 KB Output is correct
8 Correct 8 ms 49756 KB Output is correct
9 Correct 7 ms 49756 KB Output is correct
10 Correct 8 ms 49608 KB Output is correct
11 Correct 7 ms 49500 KB Output is correct
12 Correct 11 ms 49648 KB Output is correct
13 Correct 7 ms 49728 KB Output is correct
14 Correct 9 ms 49756 KB Output is correct
15 Correct 7 ms 49880 KB Output is correct
16 Correct 8 ms 49756 KB Output is correct
17 Correct 8 ms 49756 KB Output is correct
18 Correct 8 ms 49756 KB Output is correct
19 Runtime error 132 ms 159192 KB Execution killed with signal 11
20 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Runtime error 127 ms 157392 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 49496 KB Output is correct
2 Runtime error 126 ms 157324 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -