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Submission #573645

# Submission time Handle Problem Language Result Execution time Memory
573645 2022-06-07T03:56:32 Z eecs Event Hopping (BOI22_events) C++17
40 / 100
 1500 ms 484892 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010, SZ = 600;
int n, q, b[maxn], rmq[20][maxn], bel[maxn], bl[maxn], br[maxn];
int num[maxn / SZ + 5][SZ + 5], pos[maxn][SZ + 5], tmp[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 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(SZ);
        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 2 ms 2644 KB Output is correct
2 Execution timed out 1623 ms 484856 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 7 ms 7508 KB Output is correct
4 Correct 6 ms 7508 KB Output is correct
5 Correct 8 ms 7508 KB Output is correct
6 Correct 5 ms 7508 KB Output is correct
7 Correct 6 ms 7508 KB Output is correct
8 Correct 6 ms 7508 KB Output is correct
9 Correct 6 ms 7448 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 7 ms 7508 KB Output is correct
4 Correct 6 ms 7508 KB Output is correct
5 Correct 8 ms 7508 KB Output is correct
6 Correct 5 ms 7508 KB Output is correct
7 Correct 6 ms 7508 KB Output is correct
8 Correct 6 ms 7508 KB Output is correct
9 Correct 6 ms 7448 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2772 KB Output is correct
12 Correct 8 ms 7480 KB Output is correct
13 Correct 6 ms 7508 KB Output is correct
14 Correct 7 ms 7508 KB Output is correct
15 Correct 8 ms 7508 KB Output is correct
16 Correct 7 ms 7516 KB Output is correct
17 Correct 6 ms 7508 KB Output is correct
18 Correct 5 ms 7508 KB Output is correct
19 Correct 347 ms 27172 KB Output is correct
20 Correct 246 ms 27224 KB Output is correct
21 Correct 151 ms 27592 KB Output is correct
22 Correct 46 ms 27440 KB Output is correct
23 Correct 42 ms 27340 KB Output is correct
24 Correct 38 ms 27384 KB Output is correct
25 Correct 182 ms 27296 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 7 ms 7508 KB Output is correct
4 Correct 6 ms 7508 KB Output is correct
5 Correct 8 ms 7508 KB Output is correct
6 Correct 5 ms 7508 KB Output is correct
7 Correct 6 ms 7508 KB Output is correct
8 Correct 6 ms 7508 KB Output is correct
9 Correct 6 ms 7448 KB Output is correct
10 Correct 3 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 9 ms 7508 KB Output is correct
13 Correct 7 ms 7508 KB Output is correct
14 Correct 6 ms 7508 KB Output is correct
15 Correct 5 ms 7508 KB Output is correct
16 Correct 5 ms 7452 KB Output is correct
17 Correct 5 ms 7508 KB Output is correct
18 Correct 5 ms 7508 KB Output is correct
19 Correct 467 ms 484404 KB Output is correct
20 Correct 437 ms 484396 KB Output is correct
21 Correct 300 ms 484200 KB Output is correct
22 Correct 428 ms 484324 KB Output is correct
23 Correct 294 ms 484332 KB Output is correct
24 Correct 270 ms 484384 KB Output is correct
25 Correct 247 ms 483992 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1614 ms 484892 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Execution timed out 1623 ms 484856 KB Time limit exceeded
3 Halted 0 ms 0 KB -