oj.uz

Submission #573636

# Submission time Handle Problem Language Result Execution time Memory
573636 2022-06-07T03:31:27 Z eecs Event Hopping (BOI22_events) C++17
25 / 100
 1500 ms 98040 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010, SZ = 300;
int n, q, b[maxn], rmq[20][maxn];
int bel[maxn], bl[maxn], br[maxn];
array<int, 2> a[maxn];
vector<int> tr[maxn];

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n >> q;
    vector<int> V;
    for (int i = 1; i <= n; i++) {
        cin >> a[i][0] >> a[i][1], V.push_back(a[i][1]);
    }
    sort(V.begin(), V.end());
    V.resize(unique(V.begin(), V.end()) - V.begin());
    fill(b + 1, b + n + 1, n + 1);
    for (int i = 1; i <= n; i++) {
        a[i][0] = lower_bound(V.begin(), V.end(), a[i][0]) - V.begin() + 1;
        a[i][1] = lower_bound(V.begin(), V.end(), a[i][1]) - V.begin() + 1;
        b[a[i][1]] = min(b[a[i][1]], a[i][0]);
    }
    for (int i = 1; i <= n; i++) {
        br[bel[i] = (i - 1) / SZ + 1] = i;
        if (!bl[bel[i]]) bl[bel[i]] = i;
    }
    copy(b + 1, b + n + 1, rmq[0] + 1);
    for (int k = 1; k < 20; k++) {
        for (int i = 1; i + (1 << k) - 1 <= n; i++) {
            rmq[k][i] = min(rmq[k - 1][i], rmq[k - 1][i + (1 << (k - 1))]);
        }
    }
    auto qmin = [&](int l, int r) {
        int k = __lg(r - l + 1);
        return min(rmq[k][l], rmq[k][r - (1 << k) + 1]);
    };
    auto go = [&](int s, int r) {
        int lb = s + 1, rb = r, ans = 0;
        while (lb <= rb) {
            int mid = (lb + rb) / 2;
            qmin(mid, r) <= s ? lb = (ans = mid) + 1 : rb = mid - 1;
        }
        return ans;
    };
    for (int i = 1; i <= n; i++) {
        int lim = br[bel[i]];
        for (int j = go(i, lim); j && j <= lim; j = go(j, lim)) {
            tr[i].push_back(j);
        }
    }
    while (q--) {
        int s, t, ans = 0;
        cin >> s >> t;
        if (s == t) { cout << "0\n"; continue; }
        for (s = a[s][1]; s && s < a[t][0]; ans++) {
            if (1) {
                s = go(s, a[t][1]);
            } else {
                int nxt = qmin(bl[bel[s] + 1], a[t][1]);
                auto it = lower_bound(tr[s].begin(), tr[s].end(), nxt);
                if (it == tr[s].end()) { s = 0; break; }
                ans += it - tr[s].begin(), s = *it;
            }
        }
        if (a[t][0] <= s && s <= a[t][1]) cout << ans + 1 << "\n";
        else cout << "impossible\n";
    }
    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Execution timed out 1576 ms 98004 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 9 ms 3612 KB Output is correct
4 Correct 9 ms 3456 KB Output is correct
5 Correct 7 ms 3540 KB Output is correct
6 Correct 3 ms 2772 KB Output is correct
7 Correct 3 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 9 ms 3612 KB Output is correct
4 Correct 9 ms 3456 KB Output is correct
5 Correct 7 ms 3540 KB Output is correct
6 Correct 3 ms 2772 KB Output is correct
7 Correct 3 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 9 ms 3540 KB Output is correct
13 Correct 6 ms 3412 KB Output is correct
14 Correct 7 ms 3540 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2772 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 2 ms 2772 KB Output is correct
19 Execution timed out 1580 ms 4840 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 9 ms 3612 KB Output is correct
4 Correct 9 ms 3456 KB Output is correct
5 Correct 7 ms 3540 KB Output is correct
6 Correct 3 ms 2772 KB Output is correct
7 Correct 3 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 9 ms 3620 KB Output is correct
13 Correct 6 ms 3412 KB Output is correct
14 Correct 8 ms 3540 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2772 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 2 ms 2772 KB Output is correct
19 Correct 1084 ms 97968 KB Output is correct
20 Correct 597 ms 98040 KB Output is correct
21 Correct 56 ms 12308 KB Output is correct
22 Correct 427 ms 65936 KB Output is correct
23 Correct 49 ms 13848 KB Output is correct
24 Correct 61 ms 13844 KB Output is correct
25 Correct 25 ms 10964 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1586 ms 98028 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Execution timed out 1576 ms 98004 KB Time limit exceeded
3 Halted 0 ms 0 KB -