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답안 #573642

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
573642 2022-06-07T03:39:56 Z eecs Event Hopping (BOI22_events) C++17
40 / 100
 1500 ms 127056 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010, SZ = 400;
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() {
    double start = clock();
    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++) {
        for (int lim = br[bel[i]], j = go(i, lim); j && j <= lim; j = go(j, lim)) {
            tr[i].push_back(j);
        }
    }
    cerr << clock() - start << endl;
    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++) {
            int nxt;
            if (bel[s] == bel[a[t][0]] || (nxt = qmin(bl[bel[s] + 1], a[t][1])) <= s) {
                s = go(s, a[t][1]);
            } else {
                auto it = lower_bound(tr[s].begin(), tr[s].end(), nxt);
                if (it == tr[s].end()) s = 0;
                else ans += it - tr[s].begin(), s = *it;
            }
        }
        if (a[t][0] <= s && s <= a[t][1]) cout << ans + 1 << "\n";
        else cout << "impossible\n";
    }
    cerr << clock() - start << endl;
    return 0;
}

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Execution timed out 1587 ms 127020 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 9 ms 3852 KB Output is correct
4 Correct 7 ms 3624 KB Output is correct
5 Correct 8 ms 3668 KB Output is correct
6 Correct 2 ms 2772 KB Output is correct
7 Correct 2 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
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 9 ms 3852 KB Output is correct
4 Correct 7 ms 3624 KB Output is correct
5 Correct 8 ms 3668 KB Output is correct
6 Correct 2 ms 2772 KB Output is correct
7 Correct 2 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 1 ms 2644 KB Output is correct
12 Correct 9 ms 3796 KB Output is correct
13 Correct 7 ms 3668 KB Output is correct
14 Correct 7 ms 3668 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 3 ms 2900 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 2 ms 2772 KB Output is correct
19 Correct 362 ms 5528 KB Output is correct
20 Correct 593 ms 9272 KB Output is correct
21 Correct 330 ms 9444 KB Output is correct
22 Correct 36 ms 3964 KB Output is correct
23 Correct 24 ms 3796 KB Output is correct
24 Correct 22 ms 3852 KB Output is correct
25 Correct 107 ms 3592 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 9 ms 3852 KB Output is correct
4 Correct 7 ms 3624 KB Output is correct
5 Correct 8 ms 3668 KB Output is correct
6 Correct 2 ms 2772 KB Output is correct
7 Correct 2 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 8 ms 3796 KB Output is correct
13 Correct 6 ms 3596 KB Output is correct
14 Correct 7 ms 3668 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 707 ms 126772 KB Output is correct
20 Correct 682 ms 126260 KB Output is correct
21 Correct 58 ms 12324 KB Output is correct
22 Correct 513 ms 83384 KB Output is correct
23 Correct 50 ms 13868 KB Output is correct
24 Correct 68 ms 13824 KB Output is correct
25 Correct 26 ms 10856 KB Output is correct

Subtask #5
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1580 ms 127056 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Execution timed out 1587 ms 127020 KB Time limit exceeded
3 Halted 0 ms 0 KB -