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Submission #573664

# Submission time Handle Problem Language Result Execution time Memory
573664 2022-06-07T04:28:33 Z eecs Event Hopping (BOI22_events) C++17
40 / 100
 1500 ms 307612 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010, SZ = 750;
int n, q, b[maxn], rmq[17][maxn], bel[maxn], bl[maxn], br[maxn];
int num[maxn / SZ + 5][SZ + 5], tmp[SZ + 5];
short pos[maxn][SZ + 5];
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 < 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) {
        for (int i = __lg(r); ~i && r > s; i--) {
            if (rmq[i][r] > s) r -= 1 << i;
        }
        return r <= s ? 0 : r;
    };
    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];
        tr[i].reserve(R - i);
        for (int j = num[k][i - L]; j && j <= R; j = num[k][j - L]) {
            tr[i].push_back(j);
        }
        for (int j = L, k = 0; j <= R; j++) {
            while (k < tr[i].size() && tr[i][k] < j) k++;
            pos[i][j - L] = 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 = i == a[t][0] ? qmin(i, a[t][1]) : b[i];
                    for (; j >= max(s, v); j--) tmp[j - s] = j < i ? i : 0;
                }
                for (int o = s; s && s < a[t][0]; ans++) {
                    s = tmp[s - o];
                }
                break;
            }
            int nxt = qmin(bl[bel[s] + 1], a[t][1]);
            if (nxt <= s) {
                s = go(s, a[t][1]);
            } else {
                if (tr[s].empty() || nxt > tr[s].back()) { s = 0; break; }
                int i = pos[s][nxt - bl[bel[s]]];
                ans += i, s = tr[s][i];
            }
        }
        if (a[t][0] <= s && s <= a[t][1]) cout << ans + 1 << "\n";
        else cout << "impossible\n";
    }
    return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:59:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |             while (k < tr[i].size() && tr[i][k] < j) k++;
      |                    ~~^~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8916 KB Output is correct
2 Execution timed out 1598 ms 307612 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 8916 KB Output is correct
2 Correct 4 ms 8916 KB Output is correct
3 Correct 10 ms 11604 KB Output is correct
4 Correct 9 ms 11700 KB Output is correct
5 Correct 9 ms 11652 KB Output is correct
6 Correct 6 ms 11624 KB Output is correct
7 Correct 7 ms 11628 KB Output is correct
8 Correct 7 ms 11604 KB Output is correct
9 Correct 8 ms 11604 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 8916 KB Output is correct
2 Correct 4 ms 8916 KB Output is correct
3 Correct 10 ms 11604 KB Output is correct
4 Correct 9 ms 11700 KB Output is correct
5 Correct 9 ms 11652 KB Output is correct
6 Correct 6 ms 11624 KB Output is correct
7 Correct 7 ms 11628 KB Output is correct
8 Correct 7 ms 11604 KB Output is correct
9 Correct 8 ms 11604 KB Output is correct
10 Correct 5 ms 8916 KB Output is correct
11 Correct 4 ms 8948 KB Output is correct
12 Correct 9 ms 11612 KB Output is correct
13 Correct 8 ms 11604 KB Output is correct
14 Correct 9 ms 11604 KB Output is correct
15 Correct 6 ms 11604 KB Output is correct
16 Correct 7 ms 11604 KB Output is correct
17 Correct 8 ms 11604 KB Output is correct
18 Correct 8 ms 11696 KB Output is correct
19 Correct 179 ms 24252 KB Output is correct
20 Correct 313 ms 24048 KB Output is correct
21 Correct 196 ms 24324 KB Output is correct
22 Correct 53 ms 24448 KB Output is correct
23 Correct 38 ms 24236 KB Output is correct
24 Correct 37 ms 24268 KB Output is correct
25 Correct 157 ms 23840 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 8916 KB Output is correct
2 Correct 4 ms 8916 KB Output is correct
3 Correct 10 ms 11604 KB Output is correct
4 Correct 9 ms 11700 KB Output is correct
5 Correct 9 ms 11652 KB Output is correct
6 Correct 6 ms 11624 KB Output is correct
7 Correct 7 ms 11628 KB Output is correct
8 Correct 7 ms 11604 KB Output is correct
9 Correct 8 ms 11604 KB Output is correct
10 Correct 4 ms 8916 KB Output is correct
11 Correct 6 ms 8916 KB Output is correct
12 Correct 10 ms 11604 KB Output is correct
13 Correct 7 ms 11600 KB Output is correct
14 Correct 8 ms 11604 KB Output is correct
15 Correct 6 ms 11604 KB Output is correct
16 Correct 6 ms 11604 KB Output is correct
17 Correct 7 ms 11604 KB Output is correct
18 Correct 6 ms 11604 KB Output is correct
19 Correct 517 ms 307128 KB Output is correct
20 Correct 487 ms 307044 KB Output is correct
21 Correct 246 ms 306936 KB Output is correct
22 Correct 456 ms 307172 KB Output is correct
23 Correct 244 ms 307064 KB Output is correct
24 Correct 251 ms 307164 KB Output is correct
25 Correct 191 ms 306636 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1607 ms 307608 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8916 KB Output is correct
2 Execution timed out 1598 ms 307612 KB Time limit exceeded
3 Halted 0 ms 0 KB -