#include<bits/stdc++.h>
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
using namespace std;
const int N = 510, mod = 1e9 + 7;
int l[N], r[N], a[N], b[N], cnt[N << 1], inv[N], f[2][N << 1][N];
int power(int a, int p) {
if (!p) return 1;
int tmp = power(a, p >> 1);
tmp = 1LL * tmp * tmp % mod;
if (p % 2) return 1LL * tmp * a % mod;
return tmp;
}
void add(int &a, int b) {
a += b;
if (a >= mod) a -= mod;
}
int main() {
cin.tie(0) -> sync_with_stdio(0);
int n; cin >> n;
vector<int> rrh;
for(int i = 1; i <= n; i++) {
cin >> l[i] >> r[i];
rrh.push_back(l[i] - 1);
rrh.push_back(r[i]);
}
sort(rrh.begin(), rrh.end());
rrh.resize(unique(rrh.begin(), rrh.end()) - rrh.begin());
for(int i = 1; i <= n; i++) {
a[i] = upper_bound(rrh.begin(), rrh.end(), l[i] - 1) - rrh.begin();
b[i] = upper_bound(rrh.begin(), rrh.end(), r[i]) - rrh.begin();
// cout << a[i] << " " << b[i] << endl;
}
for(int i = 1; i < rrh.size(); i++) cnt[i + 1] = rrh[i] - rrh[i - 1];
// for(int i = 1; i <= rrh.size(); i++) cout << cnt[i] << " ";
for(int i = 2; i <= n; i++) inv[i] = power(i, mod - 2);
int m = rrh.size();
bool cur = 1;
for(int i = 1; i <= n; i++) {
bool pre = cur;
cur ^= 1;
for(int j = 1; j <= m; j++) for(int k = 0; k <= i; k++) f[cur][j][k] = f[pre][j][k];
int prefix = 1;
for(int j = 1; j <= a[i]; j++) for(int k = 0; k <= min(cnt[j], i); k++) add(prefix, f[pre][j][k]);
for(int j = a[i] + 1; j <= b[i]; j++) {
add(f[cur][j][1], 1LL * prefix * cnt[j] % mod);
add(prefix, f[pre][j][1]);
for(int k = 2; k <= i; k++) {
add(f[cur][j][k], 1LL * f[pre][j][k - 1] * (cnt[j] - k + 1) % mod * inv[k] % mod);
add(prefix, f[pre][j][k]);
}
}
}
int res = 0;
for(int j = 2; j <= m; j++) for(int k = 1; k <= n; k++) {
add(res, f[cur][j][k]);
}
cout << res;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:38:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
38 | for(int i = 1; i < rrh.size(); i++) cnt[i + 1] = rrh[i] - rrh[i - 1];
| ~~^~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
133 ms |
4332 KB |
Output is correct |
2 |
Correct |
134 ms |
4336 KB |
Output is correct |
3 |
Correct |
135 ms |
4304 KB |
Output is correct |
4 |
Correct |
126 ms |
4308 KB |
Output is correct |
5 |
Correct |
127 ms |
4340 KB |
Output is correct |
6 |
Correct |
149 ms |
4344 KB |
Output is correct |
7 |
Correct |
144 ms |
4332 KB |
Output is correct |
8 |
Correct |
151 ms |
4336 KB |
Output is correct |
9 |
Correct |
160 ms |
4336 KB |
Output is correct |
10 |
Correct |
147 ms |
4336 KB |
Output is correct |
11 |
Correct |
141 ms |
4340 KB |
Output is correct |
12 |
Correct |
155 ms |
4336 KB |
Output is correct |
13 |
Correct |
159 ms |
4332 KB |
Output is correct |
14 |
Correct |
137 ms |
4308 KB |
Output is correct |
15 |
Correct |
138 ms |
4348 KB |
Output is correct |
16 |
Correct |
22 ms |
1108 KB |
Output is correct |
17 |
Correct |
22 ms |
1108 KB |
Output is correct |
18 |
Correct |
22 ms |
976 KB |
Output is correct |
19 |
Correct |
27 ms |
1104 KB |
Output is correct |
20 |
Correct |
22 ms |
976 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
133 ms |
4332 KB |
Output is correct |
2 |
Correct |
134 ms |
4336 KB |
Output is correct |
3 |
Correct |
135 ms |
4304 KB |
Output is correct |
4 |
Correct |
126 ms |
4308 KB |
Output is correct |
5 |
Correct |
127 ms |
4340 KB |
Output is correct |
6 |
Correct |
149 ms |
4344 KB |
Output is correct |
7 |
Correct |
144 ms |
4332 KB |
Output is correct |
8 |
Correct |
151 ms |
4336 KB |
Output is correct |
9 |
Correct |
160 ms |
4336 KB |
Output is correct |
10 |
Correct |
147 ms |
4336 KB |
Output is correct |
11 |
Correct |
141 ms |
4340 KB |
Output is correct |
12 |
Correct |
155 ms |
4336 KB |
Output is correct |
13 |
Correct |
159 ms |
4332 KB |
Output is correct |
14 |
Correct |
137 ms |
4308 KB |
Output is correct |
15 |
Correct |
138 ms |
4348 KB |
Output is correct |
16 |
Correct |
22 ms |
1108 KB |
Output is correct |
17 |
Correct |
22 ms |
1108 KB |
Output is correct |
18 |
Correct |
22 ms |
976 KB |
Output is correct |
19 |
Correct |
27 ms |
1104 KB |
Output is correct |
20 |
Correct |
22 ms |
976 KB |
Output is correct |
21 |
Correct |
304 ms |
3992 KB |
Output is correct |
22 |
Correct |
353 ms |
4036 KB |
Output is correct |
23 |
Correct |
297 ms |
3964 KB |
Output is correct |
24 |
Correct |
313 ms |
3932 KB |
Output is correct |
25 |
Correct |
320 ms |
3944 KB |
Output is correct |
26 |
Correct |
451 ms |
3852 KB |
Output is correct |
27 |
Correct |
391 ms |
3920 KB |
Output is correct |
28 |
Correct |
434 ms |
3848 KB |
Output is correct |
29 |
Correct |
401 ms |
3840 KB |
Output is correct |
30 |
Correct |
139 ms |
4328 KB |
Output is correct |
31 |
Correct |
140 ms |
4348 KB |
Output is correct |
32 |
Correct |
134 ms |
4412 KB |
Output is correct |
33 |
Correct |
132 ms |
4340 KB |
Output is correct |
34 |
Correct |
155 ms |
4320 KB |
Output is correct |
35 |
Correct |
145 ms |
4332 KB |
Output is correct |
36 |
Correct |
140 ms |
4332 KB |
Output is correct |
37 |
Correct |
115 ms |
4344 KB |
Output is correct |
38 |
Correct |
134 ms |
4388 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
1108 KB |
Output is correct |
2 |
Correct |
4 ms |
1108 KB |
Output is correct |
3 |
Correct |
5 ms |
1100 KB |
Output is correct |
4 |
Correct |
4 ms |
1096 KB |
Output is correct |
5 |
Correct |
4 ms |
1108 KB |
Output is correct |
6 |
Correct |
5 ms |
1108 KB |
Output is correct |
7 |
Correct |
5 ms |
1108 KB |
Output is correct |
8 |
Correct |
7 ms |
1108 KB |
Output is correct |
9 |
Correct |
5 ms |
1152 KB |
Output is correct |
10 |
Correct |
5 ms |
1108 KB |
Output is correct |
11 |
Correct |
4 ms |
1108 KB |
Output is correct |
12 |
Correct |
4 ms |
1108 KB |
Output is correct |
13 |
Correct |
4 ms |
1152 KB |
Output is correct |
14 |
Correct |
4 ms |
1108 KB |
Output is correct |
15 |
Correct |
5 ms |
1108 KB |
Output is correct |
16 |
Correct |
3 ms |
724 KB |
Output is correct |
17 |
Correct |
3 ms |
716 KB |
Output is correct |
18 |
Correct |
3 ms |
724 KB |
Output is correct |
19 |
Correct |
3 ms |
716 KB |
Output is correct |
20 |
Correct |
3 ms |
724 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
133 ms |
4332 KB |
Output is correct |
2 |
Correct |
134 ms |
4336 KB |
Output is correct |
3 |
Correct |
135 ms |
4304 KB |
Output is correct |
4 |
Correct |
126 ms |
4308 KB |
Output is correct |
5 |
Correct |
127 ms |
4340 KB |
Output is correct |
6 |
Correct |
149 ms |
4344 KB |
Output is correct |
7 |
Correct |
144 ms |
4332 KB |
Output is correct |
8 |
Correct |
151 ms |
4336 KB |
Output is correct |
9 |
Correct |
160 ms |
4336 KB |
Output is correct |
10 |
Correct |
147 ms |
4336 KB |
Output is correct |
11 |
Correct |
141 ms |
4340 KB |
Output is correct |
12 |
Correct |
155 ms |
4336 KB |
Output is correct |
13 |
Correct |
159 ms |
4332 KB |
Output is correct |
14 |
Correct |
137 ms |
4308 KB |
Output is correct |
15 |
Correct |
138 ms |
4348 KB |
Output is correct |
16 |
Correct |
22 ms |
1108 KB |
Output is correct |
17 |
Correct |
22 ms |
1108 KB |
Output is correct |
18 |
Correct |
22 ms |
976 KB |
Output is correct |
19 |
Correct |
27 ms |
1104 KB |
Output is correct |
20 |
Correct |
22 ms |
976 KB |
Output is correct |
21 |
Correct |
304 ms |
3992 KB |
Output is correct |
22 |
Correct |
353 ms |
4036 KB |
Output is correct |
23 |
Correct |
297 ms |
3964 KB |
Output is correct |
24 |
Correct |
313 ms |
3932 KB |
Output is correct |
25 |
Correct |
320 ms |
3944 KB |
Output is correct |
26 |
Correct |
451 ms |
3852 KB |
Output is correct |
27 |
Correct |
391 ms |
3920 KB |
Output is correct |
28 |
Correct |
434 ms |
3848 KB |
Output is correct |
29 |
Correct |
401 ms |
3840 KB |
Output is correct |
30 |
Correct |
139 ms |
4328 KB |
Output is correct |
31 |
Correct |
140 ms |
4348 KB |
Output is correct |
32 |
Correct |
134 ms |
4412 KB |
Output is correct |
33 |
Correct |
132 ms |
4340 KB |
Output is correct |
34 |
Correct |
155 ms |
4320 KB |
Output is correct |
35 |
Correct |
145 ms |
4332 KB |
Output is correct |
36 |
Correct |
140 ms |
4332 KB |
Output is correct |
37 |
Correct |
115 ms |
4344 KB |
Output is correct |
38 |
Correct |
134 ms |
4388 KB |
Output is correct |
39 |
Correct |
5 ms |
1108 KB |
Output is correct |
40 |
Correct |
4 ms |
1108 KB |
Output is correct |
41 |
Correct |
5 ms |
1100 KB |
Output is correct |
42 |
Correct |
4 ms |
1096 KB |
Output is correct |
43 |
Correct |
4 ms |
1108 KB |
Output is correct |
44 |
Correct |
5 ms |
1108 KB |
Output is correct |
45 |
Correct |
5 ms |
1108 KB |
Output is correct |
46 |
Correct |
7 ms |
1108 KB |
Output is correct |
47 |
Correct |
5 ms |
1152 KB |
Output is correct |
48 |
Correct |
5 ms |
1108 KB |
Output is correct |
49 |
Correct |
4 ms |
1108 KB |
Output is correct |
50 |
Correct |
4 ms |
1108 KB |
Output is correct |
51 |
Correct |
4 ms |
1152 KB |
Output is correct |
52 |
Correct |
4 ms |
1108 KB |
Output is correct |
53 |
Correct |
5 ms |
1108 KB |
Output is correct |
54 |
Correct |
3 ms |
724 KB |
Output is correct |
55 |
Correct |
3 ms |
716 KB |
Output is correct |
56 |
Correct |
3 ms |
724 KB |
Output is correct |
57 |
Correct |
3 ms |
716 KB |
Output is correct |
58 |
Correct |
3 ms |
724 KB |
Output is correct |
59 |
Correct |
378 ms |
4308 KB |
Output is correct |
60 |
Correct |
343 ms |
4428 KB |
Output is correct |
61 |
Correct |
319 ms |
4336 KB |
Output is correct |
62 |
Correct |
412 ms |
4336 KB |
Output is correct |
63 |
Correct |
369 ms |
4428 KB |
Output is correct |
64 |
Correct |
470 ms |
4336 KB |
Output is correct |
65 |
Correct |
469 ms |
4308 KB |
Output is correct |
66 |
Correct |
494 ms |
4332 KB |
Output is correct |
67 |
Correct |
489 ms |
4336 KB |
Output is correct |
68 |
Correct |
450 ms |
4336 KB |
Output is correct |
69 |
Correct |
326 ms |
4352 KB |
Output is correct |
70 |
Correct |
314 ms |
4336 KB |
Output is correct |
71 |
Correct |
330 ms |
4340 KB |
Output is correct |
72 |
Correct |
326 ms |
4336 KB |
Output is correct |
73 |
Correct |
365 ms |
4340 KB |
Output is correct |
74 |
Correct |
61 ms |
980 KB |
Output is correct |
75 |
Correct |
59 ms |
1112 KB |
Output is correct |
76 |
Correct |
65 ms |
984 KB |
Output is correct |
77 |
Correct |
73 ms |
980 KB |
Output is correct |
78 |
Correct |
61 ms |
980 KB |
Output is correct |