#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
int inverse(int x) {
int base = x, power = MOD - 2;
int result = 1;
while (power > 0) {
if (power & 1) {
result = 1LL * result * base % MOD;
}
base = 1LL * base * base % MOD;
power /= 2;
}
return result;
}
void norm(int& X) {
X -= X >= MOD ? MOD : 0;
}
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int N;
cin >> N;
vector<int> A(N), B(N);
vector<int> points;
for (int i = 0; i < N; i++) {
cin >> A[i] >> B[i];
points.push_back(A[i]);
points.push_back(B[i]);
}
sort(points.begin(), points.end());
points.resize(unique(points.begin(), points.end()) - points.begin());
vector<int> new_points;
for (int i = 0; i < (int)points.size(); i++) {
new_points.push_back(points[i]);
if (i + 1 < (int)points.size() && points[i + 1] - points[i] > 1) {
new_points.push_back(points[i] + 1);
}
}
points = new_points;
int M = (int)points.size();
vector<int> weight(M);
vector<vector<int>> choose_weight(M, vector<int>(N + 1));
for (int i = 0; i < M; i++) {
weight[i] = (i == M - 1 ? 1 : points[i + 1] - points[i]);
choose_weight[i][0] = 1;
for (int j = 0; j < weight[i] && j < N; j++) {
int coefficient = 1LL * (weight[i] - j) * inverse(j + 1) % MOD;
choose_weight[i][j + 1] = 1LL * choose_weight[i][j] * coefficient % MOD;
}
}
vector<vector<int>> ways(M, vector<int>(N + 1));
vector<int> pref(M + 1);
for (int i = 0; i < M; i++) {
ways[i][0] = 1;
}
for (int i = 0; i < N; i++) {
vector<vector<int>> new_ways(M, vector<int>(N + 1));
for (int j = 0; j < M; j++) {
if (A[i] <= points[j] && points[j] <= B[i]) {
new_ways[j][1] += pref[j];
}
for (int k = 0; k < N; k++) {
norm(new_ways[j][k] += ways[j][k]);
if (A[i] <= points[j] && points[j] <= B[i]) {
norm(new_ways[j][k + 1] += ways[j][k]);
}
}
}
for (int j = 0; j < M; j++) {
pref[j + 1] = pref[j];
for (int k = 1; k <= N && k <= weight[j]; k++) {
pref[j + 1] = (pref[j + 1] + 1LL * new_ways[j][k] * choose_weight[j][k]) % MOD;
}
}
ways = new_ways;
}
cout << pref[M] << "\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1368 ms |
6676 KB |
Output is correct |
2 |
Correct |
1373 ms |
6588 KB |
Output is correct |
3 |
Correct |
1353 ms |
6620 KB |
Output is correct |
4 |
Correct |
1358 ms |
6708 KB |
Output is correct |
5 |
Correct |
1369 ms |
6532 KB |
Output is correct |
6 |
Correct |
1354 ms |
6680 KB |
Output is correct |
7 |
Correct |
1374 ms |
6828 KB |
Output is correct |
8 |
Correct |
1406 ms |
6720 KB |
Output is correct |
9 |
Correct |
1371 ms |
6632 KB |
Output is correct |
10 |
Correct |
1360 ms |
6560 KB |
Output is correct |
11 |
Correct |
1364 ms |
6680 KB |
Output is correct |
12 |
Correct |
1372 ms |
6492 KB |
Output is correct |
13 |
Correct |
1372 ms |
6552 KB |
Output is correct |
14 |
Correct |
1382 ms |
6940 KB |
Output is correct |
15 |
Correct |
1397 ms |
6980 KB |
Output is correct |
16 |
Correct |
226 ms |
1508 KB |
Output is correct |
17 |
Correct |
250 ms |
1896 KB |
Output is correct |
18 |
Correct |
238 ms |
1552 KB |
Output is correct |
19 |
Correct |
253 ms |
2008 KB |
Output is correct |
20 |
Correct |
239 ms |
1564 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1368 ms |
6676 KB |
Output is correct |
2 |
Correct |
1373 ms |
6588 KB |
Output is correct |
3 |
Correct |
1353 ms |
6620 KB |
Output is correct |
4 |
Correct |
1358 ms |
6708 KB |
Output is correct |
5 |
Correct |
1369 ms |
6532 KB |
Output is correct |
6 |
Correct |
1354 ms |
6680 KB |
Output is correct |
7 |
Correct |
1374 ms |
6828 KB |
Output is correct |
8 |
Correct |
1406 ms |
6720 KB |
Output is correct |
9 |
Correct |
1371 ms |
6632 KB |
Output is correct |
10 |
Correct |
1360 ms |
6560 KB |
Output is correct |
11 |
Correct |
1364 ms |
6680 KB |
Output is correct |
12 |
Correct |
1372 ms |
6492 KB |
Output is correct |
13 |
Correct |
1372 ms |
6552 KB |
Output is correct |
14 |
Correct |
1382 ms |
6940 KB |
Output is correct |
15 |
Correct |
1397 ms |
6980 KB |
Output is correct |
16 |
Correct |
226 ms |
1508 KB |
Output is correct |
17 |
Correct |
250 ms |
1896 KB |
Output is correct |
18 |
Correct |
238 ms |
1552 KB |
Output is correct |
19 |
Correct |
253 ms |
2008 KB |
Output is correct |
20 |
Correct |
239 ms |
1564 KB |
Output is correct |
21 |
Correct |
1091 ms |
10764 KB |
Output is correct |
22 |
Correct |
1075 ms |
10832 KB |
Output is correct |
23 |
Correct |
1088 ms |
10864 KB |
Output is correct |
24 |
Correct |
1109 ms |
10848 KB |
Output is correct |
25 |
Correct |
1061 ms |
10648 KB |
Output is correct |
26 |
Correct |
1103 ms |
10168 KB |
Output is correct |
27 |
Correct |
1089 ms |
10268 KB |
Output is correct |
28 |
Correct |
1088 ms |
10284 KB |
Output is correct |
29 |
Correct |
1137 ms |
10212 KB |
Output is correct |
30 |
Correct |
1838 ms |
12072 KB |
Output is correct |
31 |
Correct |
1846 ms |
11592 KB |
Output is correct |
32 |
Correct |
1801 ms |
11960 KB |
Output is correct |
33 |
Correct |
1854 ms |
11900 KB |
Output is correct |
34 |
Correct |
1784 ms |
11888 KB |
Output is correct |
35 |
Correct |
1274 ms |
6740 KB |
Output is correct |
36 |
Correct |
1299 ms |
6576 KB |
Output is correct |
37 |
Correct |
1337 ms |
6744 KB |
Output is correct |
38 |
Correct |
1298 ms |
6656 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
25 ms |
952 KB |
Output is correct |
2 |
Correct |
24 ms |
952 KB |
Output is correct |
3 |
Correct |
27 ms |
952 KB |
Output is correct |
4 |
Correct |
25 ms |
952 KB |
Output is correct |
5 |
Correct |
25 ms |
952 KB |
Output is correct |
6 |
Correct |
25 ms |
952 KB |
Output is correct |
7 |
Correct |
26 ms |
1176 KB |
Output is correct |
8 |
Correct |
26 ms |
952 KB |
Output is correct |
9 |
Correct |
28 ms |
1116 KB |
Output is correct |
10 |
Correct |
25 ms |
952 KB |
Output is correct |
11 |
Correct |
25 ms |
952 KB |
Output is correct |
12 |
Correct |
24 ms |
956 KB |
Output is correct |
13 |
Correct |
25 ms |
952 KB |
Output is correct |
14 |
Correct |
25 ms |
952 KB |
Output is correct |
15 |
Correct |
24 ms |
956 KB |
Output is correct |
16 |
Correct |
10 ms |
600 KB |
Output is correct |
17 |
Correct |
12 ms |
600 KB |
Output is correct |
18 |
Correct |
11 ms |
600 KB |
Output is correct |
19 |
Correct |
10 ms |
600 KB |
Output is correct |
20 |
Correct |
13 ms |
456 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1368 ms |
6676 KB |
Output is correct |
2 |
Correct |
1373 ms |
6588 KB |
Output is correct |
3 |
Correct |
1353 ms |
6620 KB |
Output is correct |
4 |
Correct |
1358 ms |
6708 KB |
Output is correct |
5 |
Correct |
1369 ms |
6532 KB |
Output is correct |
6 |
Correct |
1354 ms |
6680 KB |
Output is correct |
7 |
Correct |
1374 ms |
6828 KB |
Output is correct |
8 |
Correct |
1406 ms |
6720 KB |
Output is correct |
9 |
Correct |
1371 ms |
6632 KB |
Output is correct |
10 |
Correct |
1360 ms |
6560 KB |
Output is correct |
11 |
Correct |
1364 ms |
6680 KB |
Output is correct |
12 |
Correct |
1372 ms |
6492 KB |
Output is correct |
13 |
Correct |
1372 ms |
6552 KB |
Output is correct |
14 |
Correct |
1382 ms |
6940 KB |
Output is correct |
15 |
Correct |
1397 ms |
6980 KB |
Output is correct |
16 |
Correct |
226 ms |
1508 KB |
Output is correct |
17 |
Correct |
250 ms |
1896 KB |
Output is correct |
18 |
Correct |
238 ms |
1552 KB |
Output is correct |
19 |
Correct |
253 ms |
2008 KB |
Output is correct |
20 |
Correct |
239 ms |
1564 KB |
Output is correct |
21 |
Correct |
1091 ms |
10764 KB |
Output is correct |
22 |
Correct |
1075 ms |
10832 KB |
Output is correct |
23 |
Correct |
1088 ms |
10864 KB |
Output is correct |
24 |
Correct |
1109 ms |
10848 KB |
Output is correct |
25 |
Correct |
1061 ms |
10648 KB |
Output is correct |
26 |
Correct |
1103 ms |
10168 KB |
Output is correct |
27 |
Correct |
1089 ms |
10268 KB |
Output is correct |
28 |
Correct |
1088 ms |
10284 KB |
Output is correct |
29 |
Correct |
1137 ms |
10212 KB |
Output is correct |
30 |
Correct |
1838 ms |
12072 KB |
Output is correct |
31 |
Correct |
1846 ms |
11592 KB |
Output is correct |
32 |
Correct |
1801 ms |
11960 KB |
Output is correct |
33 |
Correct |
1854 ms |
11900 KB |
Output is correct |
34 |
Correct |
1784 ms |
11888 KB |
Output is correct |
35 |
Correct |
1274 ms |
6740 KB |
Output is correct |
36 |
Correct |
1299 ms |
6576 KB |
Output is correct |
37 |
Correct |
1337 ms |
6744 KB |
Output is correct |
38 |
Correct |
1298 ms |
6656 KB |
Output is correct |
39 |
Correct |
25 ms |
952 KB |
Output is correct |
40 |
Correct |
24 ms |
952 KB |
Output is correct |
41 |
Correct |
27 ms |
952 KB |
Output is correct |
42 |
Correct |
25 ms |
952 KB |
Output is correct |
43 |
Correct |
25 ms |
952 KB |
Output is correct |
44 |
Correct |
25 ms |
952 KB |
Output is correct |
45 |
Correct |
26 ms |
1176 KB |
Output is correct |
46 |
Correct |
26 ms |
952 KB |
Output is correct |
47 |
Correct |
28 ms |
1116 KB |
Output is correct |
48 |
Correct |
25 ms |
952 KB |
Output is correct |
49 |
Correct |
25 ms |
952 KB |
Output is correct |
50 |
Correct |
24 ms |
956 KB |
Output is correct |
51 |
Correct |
25 ms |
952 KB |
Output is correct |
52 |
Correct |
25 ms |
952 KB |
Output is correct |
53 |
Correct |
24 ms |
956 KB |
Output is correct |
54 |
Correct |
10 ms |
600 KB |
Output is correct |
55 |
Correct |
12 ms |
600 KB |
Output is correct |
56 |
Correct |
11 ms |
600 KB |
Output is correct |
57 |
Correct |
10 ms |
600 KB |
Output is correct |
58 |
Correct |
13 ms |
456 KB |
Output is correct |
59 |
Execution timed out |
2013 ms |
12644 KB |
Time limit exceeded |
60 |
Halted |
0 ms |
0 KB |
- |