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Submission #746294

# Submission time Handle Problem Language Result Execution time Memory
746294 2023-05-22T08:16:08 Z Szil Event Hopping (BOI22_events) C++14
100 / 100
 601 ms 241576 KB 
#include <bits/stdc++.h>
using namespace std;
    
const int MAXN = 100001;
const int K = 30;

struct Event {
    int s, e, idx;

    Event() {
        s = INT_MAX;
        e = INT_MAX;
        idx = 0;
    }

    bool operator<(const Event &x) const {
        return s < x.s;
    }
};

struct Node {
    Node *left, *right;
    Event best; int tl, tr;

    Node(int l_, int r_) : tl(l_), tr(r_), best() {}
    
    void expand() {
        if (left == nullptr) {
            int tm = (tl + tr) / 2;
            left = new Node(tl, tm);
            right = new Node(tm+1, tr);
        }
    }
    
    void upd(int pos, Event val) {
        if (tl == tr) {
            best = min(best, val);
        } else {
            expand();
            int m = (tl + tr) / 2;
            if (pos <= m) {
                left->upd(pos, val);
            } else {
                right->upd(pos, val);
            }
            best = min(left->best, right->best);
        }
    }
    
    Event qry(int l, int r) {
        if (l > r) return Event();
        if (l == tl && r == tr) {
            return best;
        } else {
            expand();
            int m = (tl + tr) / 2;
            return min(left->qry(l, min(r, m)), right->qry(max(l, m+1), r));
        }
    }
};
    
int down[MAXN][K];
    
int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    int n, q; cin >> n >> q;

    Node *root = new Node(1, 2e9);
    vector<Event> events(n+1);
    for (int i = 1; i <= n; i++) {
        cin >> events[i].s >> events[i].e; events[i].idx = i;
        root->upd(events[i].e, events[i]);
    }

    for (int i = 1; i <= n; i++) {
        down[i][0] = root->qry(events[i].s, events[i].e).idx;
    }
    for (int j = 1; j < K; j++) {
        for (int i = 1; i <= n; i++) {
            down[i][j] = down[down[i][j-1]][j-1];
        }
    }

    while (q--) {
        int a_, b_; cin >> a_ >> b_;
        
        if (a_ == b_) {
            cout << "0\n";
            continue;
        }

        Event a = events[a_], b = events[b_];

        if (a.e > b.e) {
            cout << "impossible\n";
            continue;
        }

        if (b.s <= a.e && a.e <= b.e) {
            cout << "1\n";
            continue;
        }

        int ans = 2;
        for (int i = K-1; i >= 0; i--) {
            int next = down[b.idx][i];
            if (next && a.e < events[next].s) {
                b = events[next];
                ans += (1 << i);
            }
        }

        b = events[down[b.idx][0]];

        if (b.s > a.e || a.e > b.e) {
            cout << "impossible\n";
            continue;
        }
        cout << ans << "\n";
    }
    return 0;
}

Compilation message

events.cpp: In constructor 'Node::Node(int, int)':
events.cpp:23:25: warning: 'Node::tr' will be initialized after [-Wreorder]
   23 |     Event best; int tl, tr;
      |                         ^~
events.cpp:23:11: warning:   'Event Node::best' [-Wreorder]
   23 |     Event best; int tl, tr;
      |           ^~~~
events.cpp:25:5: warning:   when initialized here [-Wreorder]
   25 |     Node(int l_, int r_) : tl(l_), tr(r_), best() {}
      |     ^~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 374 ms 131784 KB Output is correct
3 Correct 431 ms 138992 KB Output is correct
4 Correct 454 ms 141476 KB Output is correct
5 Correct 463 ms 151404 KB Output is correct
6 Correct 429 ms 158660 KB Output is correct
7 Correct 434 ms 155008 KB Output is correct
8 Correct 443 ms 208844 KB Output is correct
9 Correct 460 ms 241500 KB Output is correct
10 Correct 414 ms 132564 KB Output is correct
11 Correct 402 ms 160136 KB Output is correct
12 Correct 152 ms 33272 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 4 ms 2136 KB Output is correct
4 Correct 4 ms 2220 KB Output is correct
5 Correct 2 ms 508 KB Output is correct
6 Correct 3 ms 1364 KB Output is correct
7 Correct 5 ms 3924 KB Output is correct
8 Correct 6 ms 3924 KB Output is correct
9 Correct 1 ms 340 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 4 ms 2136 KB Output is correct
4 Correct 4 ms 2220 KB Output is correct
5 Correct 2 ms 508 KB Output is correct
6 Correct 3 ms 1364 KB Output is correct
7 Correct 5 ms 3924 KB Output is correct
8 Correct 6 ms 3924 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 3 ms 2132 KB Output is correct
13 Correct 4 ms 2260 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 2 ms 1364 KB Output is correct
16 Correct 5 ms 3924 KB Output is correct
17 Correct 5 ms 3832 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 40 ms 2120 KB Output is correct
20 Correct 47 ms 10120 KB Output is correct
21 Correct 37 ms 3148 KB Output is correct
22 Correct 36 ms 6728 KB Output is correct
23 Correct 42 ms 17884 KB Output is correct
24 Correct 44 ms 17888 KB Output is correct
25 Correct 74 ms 17452 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 4 ms 2136 KB Output is correct
4 Correct 4 ms 2220 KB Output is correct
5 Correct 2 ms 508 KB Output is correct
6 Correct 3 ms 1364 KB Output is correct
7 Correct 5 ms 3924 KB Output is correct
8 Correct 6 ms 3924 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 3 ms 2132 KB Output is correct
13 Correct 3 ms 2260 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 2 ms 1364 KB Output is correct
16 Correct 5 ms 3924 KB Output is correct
17 Correct 5 ms 3852 KB Output is correct
18 Correct 2 ms 456 KB Output is correct
19 Correct 344 ms 132384 KB Output is correct
20 Correct 145 ms 23796 KB Output is correct
21 Correct 318 ms 75292 KB Output is correct
22 Correct 344 ms 147276 KB Output is correct
23 Correct 494 ms 239152 KB Output is correct
24 Correct 477 ms 238996 KB Output is correct
25 Correct 66 ms 14408 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 396 ms 131660 KB Output is correct
2 Correct 424 ms 138828 KB Output is correct
3 Correct 441 ms 141480 KB Output is correct
4 Correct 466 ms 241576 KB Output is correct
5 Correct 432 ms 132476 KB Output is correct
6 Correct 539 ms 241112 KB Output is correct
7 Correct 601 ms 241124 KB Output is correct
8 Correct 511 ms 241320 KB Output is correct
9 Correct 483 ms 239192 KB Output is correct
10 Correct 546 ms 240720 KB Output is correct
11 Correct 509 ms 240588 KB Output is correct
12 Correct 549 ms 240736 KB Output is correct

Subtask #6
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 374 ms 131784 KB Output is correct
3 Correct 431 ms 138992 KB Output is correct
4 Correct 454 ms 141476 KB Output is correct
5 Correct 463 ms 151404 KB Output is correct
6 Correct 429 ms 158660 KB Output is correct
7 Correct 434 ms 155008 KB Output is correct
8 Correct 443 ms 208844 KB Output is correct
9 Correct 460 ms 241500 KB Output is correct
10 Correct 414 ms 132564 KB Output is correct
11 Correct 402 ms 160136 KB Output is correct
12 Correct 152 ms 33272 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 4 ms 2136 KB Output is correct
16 Correct 4 ms 2220 KB Output is correct
17 Correct 2 ms 508 KB Output is correct
18 Correct 3 ms 1364 KB Output is correct
19 Correct 5 ms 3924 KB Output is correct
20 Correct 6 ms 3924 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 0 ms 212 KB Output is correct
24 Correct 3 ms 2132 KB Output is correct
25 Correct 4 ms 2260 KB Output is correct
26 Correct 1 ms 468 KB Output is correct
27 Correct 2 ms 1364 KB Output is correct
28 Correct 5 ms 3924 KB Output is correct
29 Correct 5 ms 3832 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 40 ms 2120 KB Output is correct
32 Correct 47 ms 10120 KB Output is correct
33 Correct 37 ms 3148 KB Output is correct
34 Correct 36 ms 6728 KB Output is correct
35 Correct 42 ms 17884 KB Output is correct
36 Correct 44 ms 17888 KB Output is correct
37 Correct 74 ms 17452 KB Output is correct
38 Correct 0 ms 212 KB Output is correct
39 Correct 0 ms 212 KB Output is correct
40 Correct 3 ms 2132 KB Output is correct
41 Correct 3 ms 2260 KB Output is correct
42 Correct 1 ms 468 KB Output is correct
43 Correct 2 ms 1364 KB Output is correct
44 Correct 5 ms 3924 KB Output is correct
45 Correct 5 ms 3852 KB Output is correct
46 Correct 2 ms 456 KB Output is correct
47 Correct 344 ms 132384 KB Output is correct
48 Correct 145 ms 23796 KB Output is correct
49 Correct 318 ms 75292 KB Output is correct
50 Correct 344 ms 147276 KB Output is correct
51 Correct 494 ms 239152 KB Output is correct
52 Correct 477 ms 238996 KB Output is correct
53 Correct 66 ms 14408 KB Output is correct
54 Correct 396 ms 131660 KB Output is correct
55 Correct 424 ms 138828 KB Output is correct
56 Correct 441 ms 141480 KB Output is correct
57 Correct 466 ms 241576 KB Output is correct
58 Correct 432 ms 132476 KB Output is correct
59 Correct 539 ms 241112 KB Output is correct
60 Correct 601 ms 241124 KB Output is correct
61 Correct 511 ms 241320 KB Output is correct
62 Correct 483 ms 239192 KB Output is correct
63 Correct 546 ms 240720 KB Output is correct
64 Correct 509 ms 240588 KB Output is correct
65 Correct 549 ms 240736 KB Output is correct
66 Correct 1 ms 212 KB Output is correct
67 Correct 436 ms 134912 KB Output is correct
68 Correct 446 ms 138884 KB Output is correct
69 Correct 466 ms 141592 KB Output is correct
70 Correct 468 ms 151412 KB Output is correct
71 Correct 444 ms 158488 KB Output is correct
72 Correct 460 ms 154868 KB Output is correct
73 Correct 444 ms 208780 KB Output is correct
74 Correct 475 ms 241412 KB Output is correct
75 Correct 390 ms 132600 KB Output is correct
76 Correct 424 ms 160056 KB Output is correct
77 Correct 146 ms 33240 KB Output is correct
78 Correct 1 ms 212 KB Output is correct
79 Correct 4 ms 2256 KB Output is correct
80 Correct 3 ms 2260 KB Output is correct
81 Correct 1 ms 464 KB Output is correct
82 Correct 3 ms 1364 KB Output is correct
83 Correct 5 ms 3924 KB Output is correct
84 Correct 5 ms 3888 KB Output is correct
85 Correct 1 ms 468 KB Output is correct
86 Correct 39 ms 3024 KB Output is correct
87 Correct 48 ms 10128 KB Output is correct
88 Correct 37 ms 3148 KB Output is correct
89 Correct 35 ms 6732 KB Output is correct
90 Correct 41 ms 17872 KB Output is correct
91 Correct 42 ms 17892 KB Output is correct
92 Correct 51 ms 17484 KB Output is correct
93 Correct 337 ms 134272 KB Output is correct
94 Correct 157 ms 23688 KB Output is correct
95 Correct 310 ms 75292 KB Output is correct
96 Correct 348 ms 147180 KB Output is correct
97 Correct 486 ms 239232 KB Output is correct
98 Correct 453 ms 239064 KB Output is correct
99 Correct 76 ms 14408 KB Output is correct
100 Correct 552 ms 241012 KB Output is correct
101 Correct 556 ms 241228 KB Output is correct
102 Correct 504 ms 241268 KB Output is correct
103 Correct 563 ms 240808 KB Output is correct
104 Correct 511 ms 240680 KB Output is correct
105 Correct 586 ms 240728 KB Output is correct
106 Correct 216 ms 23328 KB Output is correct
107 Correct 227 ms 25680 KB Output is correct
108 Correct 341 ms 77288 KB Output is correct
109 Correct 353 ms 77388 KB Output is correct
110 Correct 540 ms 240944 KB Output is correct
111 Correct 576 ms 241096 KB Output is correct