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Submission #573652

# Submission time Handle Problem Language Result Execution time Memory
573652 2022-06-07T04:08:49 Z eecs Event Hopping (BOI22_events) C++17
40 / 100
 1500 ms 367200 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010, SZ = 600;
int n, q, b[maxn], rmq[17][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 < 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 = 16; ~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:58:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |             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 1603 ms 367200 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8916 KB Output is correct
2 Correct 4 ms 8916 KB Output is correct
3 Correct 10 ms 12296 KB Output is correct
4 Correct 8 ms 12380 KB Output is correct
5 Correct 8 ms 12372 KB Output is correct
6 Correct 6 ms 12372 KB Output is correct
7 Correct 6 ms 12372 KB Output is correct
8 Correct 6 ms 12372 KB Output is correct
9 Correct 6 ms 12280 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8916 KB Output is correct
2 Correct 4 ms 8916 KB Output is correct
3 Correct 10 ms 12296 KB Output is correct
4 Correct 8 ms 12380 KB Output is correct
5 Correct 8 ms 12372 KB Output is correct
6 Correct 6 ms 12372 KB Output is correct
7 Correct 6 ms 12372 KB Output is correct
8 Correct 6 ms 12372 KB Output is correct
9 Correct 6 ms 12280 KB Output is correct
10 Correct 5 ms 8916 KB Output is correct
11 Correct 4 ms 8916 KB Output is correct
12 Correct 10 ms 12372 KB Output is correct
13 Correct 8 ms 12316 KB Output is correct
14 Correct 11 ms 12348 KB Output is correct
15 Correct 7 ms 12400 KB Output is correct
16 Correct 8 ms 12372 KB Output is correct
17 Correct 7 ms 12372 KB Output is correct
18 Correct 6 ms 12372 KB Output is correct
19 Correct 343 ms 27228 KB Output is correct
20 Correct 273 ms 27144 KB Output is correct
21 Correct 171 ms 27428 KB Output is correct
22 Correct 56 ms 27500 KB Output is correct
23 Correct 39 ms 27284 KB Output is correct
24 Correct 49 ms 27276 KB Output is correct
25 Correct 171 ms 27012 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8916 KB Output is correct
2 Correct 4 ms 8916 KB Output is correct
3 Correct 10 ms 12296 KB Output is correct
4 Correct 8 ms 12380 KB Output is correct
5 Correct 8 ms 12372 KB Output is correct
6 Correct 6 ms 12372 KB Output is correct
7 Correct 6 ms 12372 KB Output is correct
8 Correct 6 ms 12372 KB Output is correct
9 Correct 6 ms 12280 KB Output is correct
10 Correct 5 ms 8984 KB Output is correct
11 Correct 5 ms 8916 KB Output is correct
12 Correct 8 ms 12372 KB Output is correct
13 Correct 8 ms 12372 KB Output is correct
14 Correct 8 ms 12300 KB Output is correct
15 Correct 7 ms 12320 KB Output is correct
16 Correct 7 ms 12372 KB Output is correct
17 Correct 7 ms 12272 KB Output is correct
18 Correct 6 ms 12364 KB Output is correct
19 Correct 448 ms 366888 KB Output is correct
20 Correct 443 ms 366884 KB Output is correct
21 Correct 231 ms 366624 KB Output is correct
22 Correct 419 ms 366988 KB Output is correct
23 Correct 251 ms 366984 KB Output is correct
24 Correct 257 ms 366868 KB Output is correct
25 Correct 210 ms 366540 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1595 ms 367196 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 1603 ms 367200 KB Time limit exceeded
3 Halted 0 ms 0 KB -