#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int dp[2005][501], ndp[2005][501];
int C[2005][501];
int power(int a, int b) {
int r = 1;
while (b > 0) {
if (b & 1) r = (1LL * r * a) % mod;
a = (1LL * a * a) % mod, b >>= 1;
}
return r;
}
void testCase() {
int n;
cin >> n;
vector<int> l(n + 1), r(n + 1), all;
for (int i = 1; i <= n; i++) {
cin >> l[i] >> r[i];
all.push_back(l[i]);
all.push_back(r[i]);
}
sort(all.begin(), all.end());
all.erase(unique(all.begin(), all.end()), all.end());
vector<pair<int, int>> ranges;
vector<int> range_id(all.size());
for (int i = 0; i < all.size(); i++) {
if (i > 0 && all[i - 1] + 1 <= all[i] - 1) ranges.push_back({all[i - 1] + 1, all[i] - 1});
range_id[i] = ranges.size();
ranges.push_back({all[i], all[i]});
}
auto get = [&](int x) {
return lower_bound(all.begin(), all.end(), x) - all.begin();
};
int range_cnt = ranges.size();
for (int i = 0; i < range_cnt; i++) {
auto [L, R] = ranges[i];
C[i][0] = 1;
C[i][1] = (R - L + 1) % mod;
for (int j = 2; j <= n; j++) {
if (j > R - L + 1) C[i][j] = 0;
else C[i][j] = (1LL * (1LL * C[i][j - 1] * (R - L + 1 - j + 1)) % mod * power(j, mod - 2)) % mod;
}
}
for (int j = 0; j <= range_cnt; j++) dp[j][0] = 1;
for (int i = 1; i <= n; i++) {
int L = range_id[get(l[i])], R = range_id[get(r[i])];
for (int j = L; j <= R; j++) {
for (int k = 1; k <= n; k++) {
ndp[j][k] = dp[j][k - 1];
ndp[j + 1][0] += (1LL * ndp[j][k] * C[j][k]) % mod;
if (ndp[j + 1][0] >= mod) ndp[j + 1][0] -= mod;
}
ndp[j + 1][0] += ndp[j][0];
if (ndp[j + 1][0] >= mod) ndp[j + 1][0] -= mod;
}
for (int j = R + 1; j < range_cnt; j++) {
ndp[j + 1][0] += ndp[j][0];
if (ndp[j + 1][0] >= mod) ndp[j + 1][0] -= mod;
}
for (int j = 0; j <= range_cnt; j++) {
for (int k = 0; k <= n; k++) {
dp[j][k] += ndp[j][k];
if (dp[j][k] >= mod) dp[j][k] -= mod;
ndp[j][k] = 0;
}
}
}
int ans = dp[range_cnt][0] - 1;
if (ans < 0) ans += mod;
cout << ans << "\n";
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
testCase();
return 0;
}
Compilation message
boat.cpp: In function 'void testCase()':
boat.cpp:27:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
27 | for (int i = 0; i < all.size(); i++) {
| ~~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
271 ms |
9040 KB |
Output is correct |
2 |
Correct |
280 ms |
9360 KB |
Output is correct |
3 |
Correct |
275 ms |
9200 KB |
Output is correct |
4 |
Correct |
272 ms |
9116 KB |
Output is correct |
5 |
Correct |
284 ms |
9036 KB |
Output is correct |
6 |
Correct |
283 ms |
10372 KB |
Output is correct |
7 |
Correct |
286 ms |
10648 KB |
Output is correct |
8 |
Correct |
289 ms |
10464 KB |
Output is correct |
9 |
Correct |
269 ms |
10464 KB |
Output is correct |
10 |
Correct |
270 ms |
10464 KB |
Output is correct |
11 |
Correct |
281 ms |
10460 KB |
Output is correct |
12 |
Correct |
277 ms |
10464 KB |
Output is correct |
13 |
Correct |
272 ms |
10464 KB |
Output is correct |
14 |
Correct |
272 ms |
10468 KB |
Output is correct |
15 |
Correct |
291 ms |
10468 KB |
Output is correct |
16 |
Correct |
50 ms |
6744 KB |
Output is correct |
17 |
Correct |
59 ms |
6816 KB |
Output is correct |
18 |
Correct |
51 ms |
6744 KB |
Output is correct |
19 |
Correct |
53 ms |
6744 KB |
Output is correct |
20 |
Correct |
61 ms |
6804 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
271 ms |
9040 KB |
Output is correct |
2 |
Correct |
280 ms |
9360 KB |
Output is correct |
3 |
Correct |
275 ms |
9200 KB |
Output is correct |
4 |
Correct |
272 ms |
9116 KB |
Output is correct |
5 |
Correct |
284 ms |
9036 KB |
Output is correct |
6 |
Correct |
283 ms |
10372 KB |
Output is correct |
7 |
Correct |
286 ms |
10648 KB |
Output is correct |
8 |
Correct |
289 ms |
10464 KB |
Output is correct |
9 |
Correct |
269 ms |
10464 KB |
Output is correct |
10 |
Correct |
270 ms |
10464 KB |
Output is correct |
11 |
Correct |
281 ms |
10460 KB |
Output is correct |
12 |
Correct |
277 ms |
10464 KB |
Output is correct |
13 |
Correct |
272 ms |
10464 KB |
Output is correct |
14 |
Correct |
272 ms |
10468 KB |
Output is correct |
15 |
Correct |
291 ms |
10468 KB |
Output is correct |
16 |
Correct |
50 ms |
6744 KB |
Output is correct |
17 |
Correct |
59 ms |
6816 KB |
Output is correct |
18 |
Correct |
51 ms |
6744 KB |
Output is correct |
19 |
Correct |
53 ms |
6744 KB |
Output is correct |
20 |
Correct |
61 ms |
6804 KB |
Output is correct |
21 |
Correct |
957 ms |
11616 KB |
Output is correct |
22 |
Correct |
919 ms |
11644 KB |
Output is correct |
23 |
Correct |
901 ms |
11608 KB |
Output is correct |
24 |
Correct |
925 ms |
11640 KB |
Output is correct |
25 |
Correct |
921 ms |
11600 KB |
Output is correct |
26 |
Correct |
1097 ms |
11424 KB |
Output is correct |
27 |
Correct |
1099 ms |
11444 KB |
Output is correct |
28 |
Correct |
1098 ms |
11440 KB |
Output is correct |
29 |
Correct |
1113 ms |
11356 KB |
Output is correct |
30 |
Correct |
490 ms |
11856 KB |
Output is correct |
31 |
Correct |
483 ms |
11976 KB |
Output is correct |
32 |
Correct |
511 ms |
11968 KB |
Output is correct |
33 |
Correct |
482 ms |
11860 KB |
Output is correct |
34 |
Correct |
494 ms |
11960 KB |
Output is correct |
35 |
Correct |
270 ms |
9052 KB |
Output is correct |
36 |
Correct |
272 ms |
10576 KB |
Output is correct |
37 |
Correct |
268 ms |
9208 KB |
Output is correct |
38 |
Correct |
301 ms |
9208 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
10840 KB |
Output is correct |
2 |
Correct |
13 ms |
10844 KB |
Output is correct |
3 |
Correct |
15 ms |
10904 KB |
Output is correct |
4 |
Correct |
14 ms |
10844 KB |
Output is correct |
5 |
Correct |
15 ms |
9052 KB |
Output is correct |
6 |
Correct |
16 ms |
10908 KB |
Output is correct |
7 |
Correct |
16 ms |
10844 KB |
Output is correct |
8 |
Correct |
17 ms |
10844 KB |
Output is correct |
9 |
Correct |
17 ms |
10840 KB |
Output is correct |
10 |
Correct |
17 ms |
10844 KB |
Output is correct |
11 |
Correct |
14 ms |
9052 KB |
Output is correct |
12 |
Correct |
16 ms |
9052 KB |
Output is correct |
13 |
Correct |
14 ms |
10912 KB |
Output is correct |
14 |
Correct |
14 ms |
10844 KB |
Output is correct |
15 |
Correct |
14 ms |
10844 KB |
Output is correct |
16 |
Correct |
7 ms |
6748 KB |
Output is correct |
17 |
Correct |
8 ms |
6748 KB |
Output is correct |
18 |
Correct |
6 ms |
6800 KB |
Output is correct |
19 |
Correct |
6 ms |
6796 KB |
Output is correct |
20 |
Correct |
7 ms |
7004 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
271 ms |
9040 KB |
Output is correct |
2 |
Correct |
280 ms |
9360 KB |
Output is correct |
3 |
Correct |
275 ms |
9200 KB |
Output is correct |
4 |
Correct |
272 ms |
9116 KB |
Output is correct |
5 |
Correct |
284 ms |
9036 KB |
Output is correct |
6 |
Correct |
283 ms |
10372 KB |
Output is correct |
7 |
Correct |
286 ms |
10648 KB |
Output is correct |
8 |
Correct |
289 ms |
10464 KB |
Output is correct |
9 |
Correct |
269 ms |
10464 KB |
Output is correct |
10 |
Correct |
270 ms |
10464 KB |
Output is correct |
11 |
Correct |
281 ms |
10460 KB |
Output is correct |
12 |
Correct |
277 ms |
10464 KB |
Output is correct |
13 |
Correct |
272 ms |
10464 KB |
Output is correct |
14 |
Correct |
272 ms |
10468 KB |
Output is correct |
15 |
Correct |
291 ms |
10468 KB |
Output is correct |
16 |
Correct |
50 ms |
6744 KB |
Output is correct |
17 |
Correct |
59 ms |
6816 KB |
Output is correct |
18 |
Correct |
51 ms |
6744 KB |
Output is correct |
19 |
Correct |
53 ms |
6744 KB |
Output is correct |
20 |
Correct |
61 ms |
6804 KB |
Output is correct |
21 |
Correct |
957 ms |
11616 KB |
Output is correct |
22 |
Correct |
919 ms |
11644 KB |
Output is correct |
23 |
Correct |
901 ms |
11608 KB |
Output is correct |
24 |
Correct |
925 ms |
11640 KB |
Output is correct |
25 |
Correct |
921 ms |
11600 KB |
Output is correct |
26 |
Correct |
1097 ms |
11424 KB |
Output is correct |
27 |
Correct |
1099 ms |
11444 KB |
Output is correct |
28 |
Correct |
1098 ms |
11440 KB |
Output is correct |
29 |
Correct |
1113 ms |
11356 KB |
Output is correct |
30 |
Correct |
490 ms |
11856 KB |
Output is correct |
31 |
Correct |
483 ms |
11976 KB |
Output is correct |
32 |
Correct |
511 ms |
11968 KB |
Output is correct |
33 |
Correct |
482 ms |
11860 KB |
Output is correct |
34 |
Correct |
494 ms |
11960 KB |
Output is correct |
35 |
Correct |
270 ms |
9052 KB |
Output is correct |
36 |
Correct |
272 ms |
10576 KB |
Output is correct |
37 |
Correct |
268 ms |
9208 KB |
Output is correct |
38 |
Correct |
301 ms |
9208 KB |
Output is correct |
39 |
Correct |
17 ms |
10840 KB |
Output is correct |
40 |
Correct |
13 ms |
10844 KB |
Output is correct |
41 |
Correct |
15 ms |
10904 KB |
Output is correct |
42 |
Correct |
14 ms |
10844 KB |
Output is correct |
43 |
Correct |
15 ms |
9052 KB |
Output is correct |
44 |
Correct |
16 ms |
10908 KB |
Output is correct |
45 |
Correct |
16 ms |
10844 KB |
Output is correct |
46 |
Correct |
17 ms |
10844 KB |
Output is correct |
47 |
Correct |
17 ms |
10840 KB |
Output is correct |
48 |
Correct |
17 ms |
10844 KB |
Output is correct |
49 |
Correct |
14 ms |
9052 KB |
Output is correct |
50 |
Correct |
16 ms |
9052 KB |
Output is correct |
51 |
Correct |
14 ms |
10912 KB |
Output is correct |
52 |
Correct |
14 ms |
10844 KB |
Output is correct |
53 |
Correct |
14 ms |
10844 KB |
Output is correct |
54 |
Correct |
7 ms |
6748 KB |
Output is correct |
55 |
Correct |
8 ms |
6748 KB |
Output is correct |
56 |
Correct |
6 ms |
6800 KB |
Output is correct |
57 |
Correct |
6 ms |
6796 KB |
Output is correct |
58 |
Correct |
7 ms |
7004 KB |
Output is correct |
59 |
Correct |
1200 ms |
12272 KB |
Output is correct |
60 |
Correct |
1151 ms |
12452 KB |
Output is correct |
61 |
Correct |
1172 ms |
12276 KB |
Output is correct |
62 |
Correct |
1190 ms |
12276 KB |
Output is correct |
63 |
Correct |
1201 ms |
12272 KB |
Output is correct |
64 |
Correct |
1475 ms |
12448 KB |
Output is correct |
65 |
Correct |
1497 ms |
12272 KB |
Output is correct |
66 |
Correct |
1478 ms |
12272 KB |
Output is correct |
67 |
Correct |
1483 ms |
12268 KB |
Output is correct |
68 |
Correct |
1482 ms |
12268 KB |
Output is correct |
69 |
Correct |
1144 ms |
12372 KB |
Output is correct |
70 |
Correct |
1147 ms |
12276 KB |
Output is correct |
71 |
Correct |
1157 ms |
12268 KB |
Output is correct |
72 |
Correct |
1159 ms |
12276 KB |
Output is correct |
73 |
Correct |
1155 ms |
12268 KB |
Output is correct |
74 |
Correct |
118 ms |
6748 KB |
Output is correct |
75 |
Correct |
127 ms |
6744 KB |
Output is correct |
76 |
Correct |
118 ms |
6900 KB |
Output is correct |
77 |
Correct |
121 ms |
8856 KB |
Output is correct |
78 |
Correct |
125 ms |
8860 KB |
Output is correct |