#include <bits/stdc++.h>
using namespace std;
const int N = 200'000 + 10;
int n, q;
struct Event {
int st, ed, idx;
} a[N];
int rvs[N];
int lg[N];
int f[N][19];
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> q;
for (int i = 1; i <= n; ++i) cin >> a[i].st >> a[i].ed, a[i].idx = i;
sort(a + 1, a + n + 1, [&](const auto& a, const auto& b) { return a.ed < b.ed; });
for (int i = 1; i <= n; ++i) rvs[a[i].idx] = i;
for (int i = 2; i < N; ++i) lg[i] = lg[i >> 1] + 1;
{ //init
vector<int> rrh;
for (int i = 1; i <= n; ++i) {
rrh.push_back(a[i].st);
rrh.push_back(a[i].ed);
}
sort(rrh.begin(), rrh.end());
rrh.erase(unique(rrh.begin(), rrh.end()), rrh.end());
a[0] = {1'000'000, 1'000'000};
vector<vector<int>> save(rrh.size() + 1);
for (int i = 1; i <= n; ++i) {
a[i].st = upper_bound(rrh.begin(), rrh.end(), a[i].st) - rrh.begin();
a[i].ed = upper_bound(rrh.begin(), rrh.end(), a[i].ed) - rrh.begin();
save[a[i].ed].push_back(i);
}
vector<array<int, 19>> st(rrh.size() + 1);
using pii = pair<int, int>;
priority_queue<pii, vector<pii>, greater<>> q;
for (int i = 1; i <= rrh.size(); ++i) {
for (const auto& idx : save[i]) q.push({a[idx].st, idx});
while (q.size() && a[q.top().second].ed < i) q.pop();
st[i][0] = (!q.size() ? 0 : q.top().second);
}
for (int j = 1; j <= 18; ++j) {
for (int i = 1; i + (1 << j) - 1 <= rrh.size(); ++i) {
int lt = st[i][j - 1], rt = st[i + (1 << j - 1)][j - 1];
st[i][j] = (a[lt].st < a[rt].st ? lt : rt);
}
}
auto get = [&](int l, int r) {
int j = lg[r - l + 1];
int lt = st[l][j], rt = st[r - (1 << j) + 1][j];
return a[lt].st < a[rt].st ? lt : rt;
};
for (int i = 1; i <= n; ++i) f[i][0] = get(a[i].st, a[i].ed);
}
auto in = [&](int x, int y) {
return a[y].st <= a[x].ed && a[x].ed <= a[y].ed;
};
for (int j = 1; j <= 18; ++j) {
for (int i = n; i >= 1; --i) f[i][j] = f[f[i][j - 1]][j - 1];
}
while (q--) {
int x, y; cin >> x >> y;
x = rvs[x]; y = rvs[y];
if (in(x, y)) { cout << 1 - (x == y) << "\n"; continue; }
if (a[x].st >= a[y].ed) { cout << "impossible\n"; continue; }
int answer = 1;
for (int i = 18; i >= 0; --i) {
if (!in(x, f[y][i]) && a[f[y][i]].ed >= a[x].ed) {
answer += (1 << i);
y = f[y][i];
}
} y = f[y][0];
if (!in(x, y)) { cout << "impossible\n"; continue; }
cout << answer + (x != y) << "\n";
}
}
Compilation message
events.cpp: In function 'int32_t main()':
events.cpp:45:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
45 | for (int i = 1; i <= rrh.size(); ++i) {
| ~~^~~~~~~~~~~~~
events.cpp:52:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
52 | for (int i = 1; i + (1 << j) - 1 <= rrh.size(); ++i) {
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
events.cpp:53:52: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
53 | int lt = st[i][j - 1], rt = st[i + (1 << j - 1)][j - 1];
| ~~^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Correct |
84 ms |
27844 KB |
Output is correct |
3 |
Correct |
74 ms |
27784 KB |
Output is correct |
4 |
Correct |
73 ms |
27620 KB |
Output is correct |
5 |
Correct |
74 ms |
29636 KB |
Output is correct |
6 |
Correct |
70 ms |
30588 KB |
Output is correct |
7 |
Correct |
90 ms |
30956 KB |
Output is correct |
8 |
Correct |
80 ms |
38432 KB |
Output is correct |
9 |
Correct |
80 ms |
38392 KB |
Output is correct |
10 |
Correct |
78 ms |
28732 KB |
Output is correct |
11 |
Correct |
88 ms |
32572 KB |
Output is correct |
12 |
Correct |
57 ms |
26316 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2420 KB |
Output is correct |
2 |
Correct |
1 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2652 KB |
Output is correct |
4 |
Correct |
1 ms |
2652 KB |
Output is correct |
5 |
Correct |
1 ms |
2652 KB |
Output is correct |
6 |
Correct |
1 ms |
2652 KB |
Output is correct |
7 |
Correct |
1 ms |
2652 KB |
Output is correct |
8 |
Correct |
1 ms |
2664 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2420 KB |
Output is correct |
2 |
Correct |
1 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2652 KB |
Output is correct |
4 |
Correct |
1 ms |
2652 KB |
Output is correct |
5 |
Correct |
1 ms |
2652 KB |
Output is correct |
6 |
Correct |
1 ms |
2652 KB |
Output is correct |
7 |
Correct |
1 ms |
2652 KB |
Output is correct |
8 |
Correct |
1 ms |
2664 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
10 |
Correct |
1 ms |
2392 KB |
Output is correct |
11 |
Correct |
1 ms |
2396 KB |
Output is correct |
12 |
Correct |
1 ms |
2524 KB |
Output is correct |
13 |
Correct |
2 ms |
2652 KB |
Output is correct |
14 |
Correct |
1 ms |
2648 KB |
Output is correct |
15 |
Correct |
1 ms |
2652 KB |
Output is correct |
16 |
Correct |
1 ms |
2652 KB |
Output is correct |
17 |
Correct |
1 ms |
2652 KB |
Output is correct |
18 |
Correct |
1 ms |
2396 KB |
Output is correct |
19 |
Correct |
27 ms |
6276 KB |
Output is correct |
20 |
Correct |
25 ms |
6560 KB |
Output is correct |
21 |
Correct |
39 ms |
6624 KB |
Output is correct |
22 |
Correct |
21 ms |
6656 KB |
Output is correct |
23 |
Correct |
20 ms |
6536 KB |
Output is correct |
24 |
Correct |
22 ms |
6536 KB |
Output is correct |
25 |
Correct |
22 ms |
6024 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2420 KB |
Output is correct |
2 |
Correct |
1 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2652 KB |
Output is correct |
4 |
Correct |
1 ms |
2652 KB |
Output is correct |
5 |
Correct |
1 ms |
2652 KB |
Output is correct |
6 |
Correct |
1 ms |
2652 KB |
Output is correct |
7 |
Correct |
1 ms |
2652 KB |
Output is correct |
8 |
Correct |
1 ms |
2664 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
10 |
Correct |
1 ms |
2508 KB |
Output is correct |
11 |
Correct |
1 ms |
2508 KB |
Output is correct |
12 |
Correct |
2 ms |
2652 KB |
Output is correct |
13 |
Correct |
2 ms |
2648 KB |
Output is correct |
14 |
Correct |
1 ms |
2652 KB |
Output is correct |
15 |
Correct |
2 ms |
2652 KB |
Output is correct |
16 |
Correct |
1 ms |
2660 KB |
Output is correct |
17 |
Correct |
1 ms |
2856 KB |
Output is correct |
18 |
Correct |
1 ms |
2392 KB |
Output is correct |
19 |
Correct |
51 ms |
28340 KB |
Output is correct |
20 |
Correct |
46 ms |
27612 KB |
Output is correct |
21 |
Correct |
56 ms |
26756 KB |
Output is correct |
22 |
Correct |
53 ms |
31948 KB |
Output is correct |
23 |
Correct |
57 ms |
38344 KB |
Output is correct |
24 |
Correct |
59 ms |
38148 KB |
Output is correct |
25 |
Correct |
33 ms |
17360 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
90 ms |
28624 KB |
Output is correct |
2 |
Correct |
69 ms |
28620 KB |
Output is correct |
3 |
Correct |
86 ms |
28624 KB |
Output is correct |
4 |
Correct |
74 ms |
38568 KB |
Output is correct |
5 |
Correct |
77 ms |
28732 KB |
Output is correct |
6 |
Correct |
86 ms |
38352 KB |
Output is correct |
7 |
Correct |
96 ms |
38352 KB |
Output is correct |
8 |
Correct |
97 ms |
38456 KB |
Output is correct |
9 |
Correct |
65 ms |
38148 KB |
Output is correct |
10 |
Correct |
77 ms |
38348 KB |
Output is correct |
11 |
Correct |
79 ms |
38460 KB |
Output is correct |
12 |
Correct |
77 ms |
38348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Correct |
84 ms |
27844 KB |
Output is correct |
3 |
Correct |
74 ms |
27784 KB |
Output is correct |
4 |
Correct |
73 ms |
27620 KB |
Output is correct |
5 |
Correct |
74 ms |
29636 KB |
Output is correct |
6 |
Correct |
70 ms |
30588 KB |
Output is correct |
7 |
Correct |
90 ms |
30956 KB |
Output is correct |
8 |
Correct |
80 ms |
38432 KB |
Output is correct |
9 |
Correct |
80 ms |
38392 KB |
Output is correct |
10 |
Correct |
78 ms |
28732 KB |
Output is correct |
11 |
Correct |
88 ms |
32572 KB |
Output is correct |
12 |
Correct |
57 ms |
26316 KB |
Output is correct |
13 |
Correct |
1 ms |
2420 KB |
Output is correct |
14 |
Correct |
1 ms |
2396 KB |
Output is correct |
15 |
Correct |
1 ms |
2652 KB |
Output is correct |
16 |
Correct |
1 ms |
2652 KB |
Output is correct |
17 |
Correct |
1 ms |
2652 KB |
Output is correct |
18 |
Correct |
1 ms |
2652 KB |
Output is correct |
19 |
Correct |
1 ms |
2652 KB |
Output is correct |
20 |
Correct |
1 ms |
2664 KB |
Output is correct |
21 |
Correct |
1 ms |
2396 KB |
Output is correct |
22 |
Correct |
1 ms |
2392 KB |
Output is correct |
23 |
Correct |
1 ms |
2396 KB |
Output is correct |
24 |
Correct |
1 ms |
2524 KB |
Output is correct |
25 |
Correct |
2 ms |
2652 KB |
Output is correct |
26 |
Correct |
1 ms |
2648 KB |
Output is correct |
27 |
Correct |
1 ms |
2652 KB |
Output is correct |
28 |
Correct |
1 ms |
2652 KB |
Output is correct |
29 |
Correct |
1 ms |
2652 KB |
Output is correct |
30 |
Correct |
1 ms |
2396 KB |
Output is correct |
31 |
Correct |
27 ms |
6276 KB |
Output is correct |
32 |
Correct |
25 ms |
6560 KB |
Output is correct |
33 |
Correct |
39 ms |
6624 KB |
Output is correct |
34 |
Correct |
21 ms |
6656 KB |
Output is correct |
35 |
Correct |
20 ms |
6536 KB |
Output is correct |
36 |
Correct |
22 ms |
6536 KB |
Output is correct |
37 |
Correct |
22 ms |
6024 KB |
Output is correct |
38 |
Correct |
1 ms |
2508 KB |
Output is correct |
39 |
Correct |
1 ms |
2508 KB |
Output is correct |
40 |
Correct |
2 ms |
2652 KB |
Output is correct |
41 |
Correct |
2 ms |
2648 KB |
Output is correct |
42 |
Correct |
1 ms |
2652 KB |
Output is correct |
43 |
Correct |
2 ms |
2652 KB |
Output is correct |
44 |
Correct |
1 ms |
2660 KB |
Output is correct |
45 |
Correct |
1 ms |
2856 KB |
Output is correct |
46 |
Correct |
1 ms |
2392 KB |
Output is correct |
47 |
Correct |
51 ms |
28340 KB |
Output is correct |
48 |
Correct |
46 ms |
27612 KB |
Output is correct |
49 |
Correct |
56 ms |
26756 KB |
Output is correct |
50 |
Correct |
53 ms |
31948 KB |
Output is correct |
51 |
Correct |
57 ms |
38344 KB |
Output is correct |
52 |
Correct |
59 ms |
38148 KB |
Output is correct |
53 |
Correct |
33 ms |
17360 KB |
Output is correct |
54 |
Correct |
90 ms |
28624 KB |
Output is correct |
55 |
Correct |
69 ms |
28620 KB |
Output is correct |
56 |
Correct |
86 ms |
28624 KB |
Output is correct |
57 |
Correct |
74 ms |
38568 KB |
Output is correct |
58 |
Correct |
77 ms |
28732 KB |
Output is correct |
59 |
Correct |
86 ms |
38352 KB |
Output is correct |
60 |
Correct |
96 ms |
38352 KB |
Output is correct |
61 |
Correct |
97 ms |
38456 KB |
Output is correct |
62 |
Correct |
65 ms |
38148 KB |
Output is correct |
63 |
Correct |
77 ms |
38348 KB |
Output is correct |
64 |
Correct |
79 ms |
38460 KB |
Output is correct |
65 |
Correct |
77 ms |
38348 KB |
Output is correct |
66 |
Correct |
1 ms |
2396 KB |
Output is correct |
67 |
Correct |
77 ms |
28632 KB |
Output is correct |
68 |
Correct |
79 ms |
28612 KB |
Output is correct |
69 |
Correct |
79 ms |
28624 KB |
Output is correct |
70 |
Correct |
77 ms |
29596 KB |
Output is correct |
71 |
Correct |
81 ms |
30516 KB |
Output is correct |
72 |
Correct |
76 ms |
30776 KB |
Output is correct |
73 |
Correct |
85 ms |
38352 KB |
Output is correct |
74 |
Correct |
86 ms |
38352 KB |
Output is correct |
75 |
Correct |
106 ms |
28644 KB |
Output is correct |
76 |
Correct |
86 ms |
32460 KB |
Output is correct |
77 |
Correct |
57 ms |
26328 KB |
Output is correct |
78 |
Correct |
1 ms |
2396 KB |
Output is correct |
79 |
Correct |
1 ms |
2652 KB |
Output is correct |
80 |
Correct |
2 ms |
2652 KB |
Output is correct |
81 |
Correct |
1 ms |
2652 KB |
Output is correct |
82 |
Correct |
1 ms |
2652 KB |
Output is correct |
83 |
Correct |
1 ms |
2652 KB |
Output is correct |
84 |
Correct |
1 ms |
2652 KB |
Output is correct |
85 |
Correct |
1 ms |
2396 KB |
Output is correct |
86 |
Correct |
25 ms |
6208 KB |
Output is correct |
87 |
Correct |
29 ms |
6368 KB |
Output is correct |
88 |
Correct |
30 ms |
6552 KB |
Output is correct |
89 |
Correct |
21 ms |
6628 KB |
Output is correct |
90 |
Correct |
29 ms |
6436 KB |
Output is correct |
91 |
Correct |
21 ms |
6616 KB |
Output is correct |
92 |
Correct |
21 ms |
6280 KB |
Output is correct |
93 |
Correct |
47 ms |
28368 KB |
Output is correct |
94 |
Correct |
43 ms |
27620 KB |
Output is correct |
95 |
Correct |
59 ms |
26860 KB |
Output is correct |
96 |
Correct |
52 ms |
31952 KB |
Output is correct |
97 |
Correct |
53 ms |
38348 KB |
Output is correct |
98 |
Correct |
55 ms |
38140 KB |
Output is correct |
99 |
Correct |
23 ms |
17360 KB |
Output is correct |
100 |
Correct |
82 ms |
38592 KB |
Output is correct |
101 |
Correct |
88 ms |
38352 KB |
Output is correct |
102 |
Correct |
100 ms |
38352 KB |
Output is correct |
103 |
Correct |
73 ms |
38440 KB |
Output is correct |
104 |
Correct |
71 ms |
38352 KB |
Output is correct |
105 |
Correct |
73 ms |
38352 KB |
Output is correct |
106 |
Correct |
75 ms |
25300 KB |
Output is correct |
107 |
Correct |
79 ms |
27856 KB |
Output is correct |
108 |
Correct |
75 ms |
27088 KB |
Output is correct |
109 |
Correct |
73 ms |
27088 KB |
Output is correct |
110 |
Correct |
93 ms |
38468 KB |
Output is correct |
111 |
Correct |
100 ms |
38492 KB |
Output is correct |