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Submission #573679

# Submission time Handle Problem Language Result Execution time Memory
573679 2022-06-07T05:00:18 Z eecs Event Hopping (BOI22_events) C++17
25 / 100
 777 ms 524288 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010, SZ = 1500;
int n, q, b[maxn], rmq[17][maxn], bel[maxn], bl[maxn], br[maxn];
int num[maxn / SZ + 5][SZ + 5], tmp[maxn], sz[maxn], rb[maxn];
short pos[maxn][SZ + 5], tr[maxn][SZ + 5];
array<int, 2> a[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 < 17; k++) {
        memcpy(rmq[k], rmq[k - 1], sizeof(rmq[k]));
        for (int i = (1 << (k - 1)) + 1; i <= n; i++) {
            rmq[k][i] = min(rmq[k][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 + (1 << k) - 1], rmq[k][r]);
    };
    auto go = [&](int s, int r) {
        r = min(r, rb[s]);
        if (b[r] <= s) return r;
        for (int i = __lg(r - s + 1); ~i && r > s; i--) {
            if (rmq[i][r] > s) r -= 1 << i;
        }
        return r <= s ? 0 : r;
    };
    for (int i = 1; i <= n; i++) {
        rb[i] = n, rb[i] = go(i, n);
    }
    for (int k = 1; k <= bel[n]; k++) {
        for (int i = br[k], j = br[k]; i >= bl[k]; i--) {
            for (; j >= max(bl[k], b[i]); j--) num[k][j - bl[k]] = j < i ? i : 0;
        }
    }
    for (int i = 1; i <= n; i++) {
        int k = bel[i], L = bl[k], R = br[k];
        for (int j = num[k][i - L]; j && j <= R; j = num[k][j - L]) {
            tr[i][sz[i]++] = j - L;
        }
        for (int j = 0, k = 0; j <= R - L; j++) {
            while (k < sz[i] && tr[i][k] < j) k++;
            pos[i][j] = k;
        }
    }
    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 (bel[s] == bel[a[t][0]]) {
                for (int i = a[t][0], j = a[t][0]; i >= s; i--) {
                    int v = max(s, i == a[t][0] ? qmin(i, a[t][1]) : b[i]);
                    for (; j >= v; j--) tmp[j] = j < i ? i : 0;
                }
                for (; s && s < a[t][0]; ans++) s = tmp[s];
                break;
            }
            int nxt = qmin(bl[bel[s] + 1], a[t][1]);
            if (nxt <= s) {
                s = go(s, a[t][1]);
            } else {
                if (!sz[s] || nxt - bl[bel[s]] > tr[s][sz[s] - 1]) { s = 0; break; }
                int i = pos[s][nxt - bl[bel[s]]];
                ans += i, s = bl[bel[s]] + tr[s][i];
                if (s < a[t][0]) s = go(s, a[t][1]), ans++;
            }
        }
        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 3 ms 6612 KB Output is correct
2 Runtime error 668 ms 524288 KB Execution killed with signal 9
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6612 KB Output is correct
2 Correct 3 ms 6612 KB Output is correct
3 Correct 9 ms 12468 KB Output is correct
4 Correct 8 ms 12524 KB Output is correct
5 Correct 10 ms 12500 KB Output is correct
6 Correct 7 ms 11092 KB Output is correct
7 Correct 10 ms 12500 KB Output is correct
8 Correct 7 ms 12500 KB Output is correct
9 Correct 7 ms 9556 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6612 KB Output is correct
2 Correct 3 ms 6612 KB Output is correct
3 Correct 9 ms 12468 KB Output is correct
4 Correct 8 ms 12524 KB Output is correct
5 Correct 10 ms 12500 KB Output is correct
6 Correct 7 ms 11092 KB Output is correct
7 Correct 10 ms 12500 KB Output is correct
8 Correct 7 ms 12500 KB Output is correct
9 Correct 7 ms 9556 KB Output is correct
10 Correct 3 ms 6612 KB Output is correct
11 Correct 3 ms 6612 KB Output is correct
12 Correct 9 ms 12500 KB Output is correct
13 Correct 8 ms 12492 KB Output is correct
14 Correct 8 ms 12500 KB Output is correct
15 Correct 8 ms 11092 KB Output is correct
16 Correct 7 ms 12500 KB Output is correct
17 Correct 7 ms 12500 KB Output is correct
18 Correct 6 ms 9500 KB Output is correct
19 Correct 158 ms 36852 KB Output is correct
20 Correct 241 ms 36784 KB Output is correct
21 Correct 225 ms 36948 KB Output is correct
22 Correct 61 ms 29688 KB Output is correct
23 Correct 54 ms 36884 KB Output is correct
24 Correct 47 ms 36860 KB Output is correct
25 Correct 137 ms 36536 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6612 KB Output is correct
2 Correct 3 ms 6612 KB Output is correct
3 Correct 9 ms 12468 KB Output is correct
4 Correct 8 ms 12524 KB Output is correct
5 Correct 10 ms 12500 KB Output is correct
6 Correct 7 ms 11092 KB Output is correct
7 Correct 10 ms 12500 KB Output is correct
8 Correct 7 ms 12500 KB Output is correct
9 Correct 7 ms 9556 KB Output is correct
10 Correct 3 ms 6612 KB Output is correct
11 Correct 3 ms 6612 KB Output is correct
12 Correct 9 ms 12500 KB Output is correct
13 Correct 7 ms 12560 KB Output is correct
14 Correct 7 ms 12500 KB Output is correct
15 Correct 6 ms 11092 KB Output is correct
16 Correct 8 ms 12500 KB Output is correct
17 Correct 7 ms 12440 KB Output is correct
18 Correct 5 ms 9556 KB Output is correct
19 Runtime error 680 ms 524288 KB Execution killed with signal 9
20 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Runtime error 777 ms 524288 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6612 KB Output is correct
2 Runtime error 668 ms 524288 KB Execution killed with signal 9
3 Halted 0 ms 0 KB -