#include <iostream>
#include <array>
#include <algorithm>
#include <vector>
#define ll long long
using namespace std;
const ll M = 1e9 + 7;
vector<array<ll, 3> > V;
vector <array<ll, 2> > U;
bool B[500];
ll dp[500], C[501];
ll n, a, b, s, z, p, f, cnt, tmp, cur, fact[501], inv[501];
int main() {
cin.tie(0);
ios::sync_with_stdio(0);
cin >> n;
fact[0] = fact[1] = inv[0] = inv[1] = 1;
for (ll i=2; i<=n; ++i) {
fact[i] = fact[i-1] * i;
fact[i] %= M;
inv[i] = (M-(((M/i) * inv[M%i])%M))%M;
}
for (int i=2; i<=n; ++i) {
inv[i] *= inv[i-1];
inv[i] %= M;
}
for (int i=0; i<n; ++i) {
cin >> a >> b;
V.push_back({a, i, 0});
V.push_back({b+1, i, 1});
}
sort(V.begin(), V.end());
for (int i=0; i+1<V.size(); ++i) {
if (!V[i][2]) {
B[V[i][1]] = 1;
}
else {
B[V[i][1]] = 0;
}
z = V[i+1][0]-V[i][0];
if (!z) continue;
U.clear();
s = 1;
for (int j=0; j<n; ++j) {
if (B[j]) U.push_back({j, s});
s += dp[j];
s %= M;
}
for (ll j=1; j<=U.size(); ++j) {
if (j > 1 && z < 2) {
C[j] = 0;
continue;
}
if (j == 1) {
C[j] = z;
continue;
}
else if (j == 2) {
C[j] = ((z * (z-1))/2) % M;
continue;
}
C[j] = 0;
p = (z * (z-1))%M;
for (ll k=2; k<=min(j, z); ++k) {
cur = 1;
cur *= (((fact[j-2] * inv[j-k])%M) * inv[k-2])%M;
cur *= (p * inv[k]) % M;
cur %= M;
C[j] += cur;
C[j] %= M;
p *= (z-k);
p %= M;
}
}
for (int j=0; j<U.size(); ++j) {
for (int k=j; k<U.size(); ++k) {
//cout << U[j][0] << " " << U[k][0] << ":" << U[j][1] << "*" << C[k-j+1] << endl;
dp[U[k][0]] += ((U[j][1] * C[k-j+1]) % M);
dp[U[k][0]] %= M;
}
}
/*for (int j=0; j<n; ++j) {
cout << dp[j] << " ";
}
cout << endl;*/
}
for (int i=0; i<n; ++i) {
f += dp[i];
f %= M;
}
cout << f << '\n';
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:35:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | for (int i=0; i+1<V.size(); ++i) {
| ~~~^~~~~~~~~
boat.cpp:51:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
51 | for (ll j=1; j<=U.size(); ++j) {
| ~^~~~~~~~~~
boat.cpp:77:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
77 | for (int j=0; j<U.size(); ++j) {
| ~^~~~~~~~~
boat.cpp:78:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
78 | for (int k=j; k<U.size(); ++k) {
| ~^~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
332 KB |
Output is correct |
2 |
Correct |
2 ms |
340 KB |
Output is correct |
3 |
Correct |
2 ms |
328 KB |
Output is correct |
4 |
Correct |
2 ms |
340 KB |
Output is correct |
5 |
Correct |
2 ms |
340 KB |
Output is correct |
6 |
Correct |
3 ms |
340 KB |
Output is correct |
7 |
Correct |
2 ms |
340 KB |
Output is correct |
8 |
Correct |
2 ms |
332 KB |
Output is correct |
9 |
Correct |
2 ms |
332 KB |
Output is correct |
10 |
Correct |
2 ms |
340 KB |
Output is correct |
11 |
Correct |
2 ms |
340 KB |
Output is correct |
12 |
Correct |
2 ms |
340 KB |
Output is correct |
13 |
Correct |
3 ms |
340 KB |
Output is correct |
14 |
Correct |
2 ms |
340 KB |
Output is correct |
15 |
Correct |
2 ms |
328 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
384 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
332 KB |
Output is correct |
2 |
Correct |
2 ms |
340 KB |
Output is correct |
3 |
Correct |
2 ms |
328 KB |
Output is correct |
4 |
Correct |
2 ms |
340 KB |
Output is correct |
5 |
Correct |
2 ms |
340 KB |
Output is correct |
6 |
Correct |
3 ms |
340 KB |
Output is correct |
7 |
Correct |
2 ms |
340 KB |
Output is correct |
8 |
Correct |
2 ms |
332 KB |
Output is correct |
9 |
Correct |
2 ms |
332 KB |
Output is correct |
10 |
Correct |
2 ms |
340 KB |
Output is correct |
11 |
Correct |
2 ms |
340 KB |
Output is correct |
12 |
Correct |
2 ms |
340 KB |
Output is correct |
13 |
Correct |
3 ms |
340 KB |
Output is correct |
14 |
Correct |
2 ms |
340 KB |
Output is correct |
15 |
Correct |
2 ms |
328 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
384 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
56 ms |
368 KB |
Output is correct |
22 |
Correct |
54 ms |
340 KB |
Output is correct |
23 |
Correct |
48 ms |
328 KB |
Output is correct |
24 |
Correct |
54 ms |
340 KB |
Output is correct |
25 |
Correct |
55 ms |
340 KB |
Output is correct |
26 |
Correct |
124 ms |
340 KB |
Output is correct |
27 |
Correct |
124 ms |
340 KB |
Output is correct |
28 |
Correct |
120 ms |
368 KB |
Output is correct |
29 |
Correct |
120 ms |
372 KB |
Output is correct |
30 |
Correct |
2 ms |
340 KB |
Output is correct |
31 |
Correct |
3 ms |
340 KB |
Output is correct |
32 |
Correct |
3 ms |
340 KB |
Output is correct |
33 |
Correct |
2 ms |
328 KB |
Output is correct |
34 |
Correct |
2 ms |
340 KB |
Output is correct |
35 |
Correct |
3 ms |
340 KB |
Output is correct |
36 |
Correct |
2 ms |
340 KB |
Output is correct |
37 |
Correct |
2 ms |
340 KB |
Output is correct |
38 |
Correct |
2 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
340 KB |
Output is correct |
2 |
Correct |
2 ms |
340 KB |
Output is correct |
3 |
Correct |
2 ms |
340 KB |
Output is correct |
4 |
Correct |
2 ms |
340 KB |
Output is correct |
5 |
Correct |
2 ms |
340 KB |
Output is correct |
6 |
Correct |
4 ms |
340 KB |
Output is correct |
7 |
Correct |
5 ms |
328 KB |
Output is correct |
8 |
Correct |
4 ms |
340 KB |
Output is correct |
9 |
Correct |
4 ms |
340 KB |
Output is correct |
10 |
Correct |
4 ms |
340 KB |
Output is correct |
11 |
Correct |
2 ms |
340 KB |
Output is correct |
12 |
Correct |
2 ms |
320 KB |
Output is correct |
13 |
Correct |
2 ms |
340 KB |
Output is correct |
14 |
Correct |
2 ms |
320 KB |
Output is correct |
15 |
Correct |
2 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
320 KB |
Output is correct |
17 |
Correct |
1 ms |
320 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
2 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
332 KB |
Output is correct |
2 |
Correct |
2 ms |
340 KB |
Output is correct |
3 |
Correct |
2 ms |
328 KB |
Output is correct |
4 |
Correct |
2 ms |
340 KB |
Output is correct |
5 |
Correct |
2 ms |
340 KB |
Output is correct |
6 |
Correct |
3 ms |
340 KB |
Output is correct |
7 |
Correct |
2 ms |
340 KB |
Output is correct |
8 |
Correct |
2 ms |
332 KB |
Output is correct |
9 |
Correct |
2 ms |
332 KB |
Output is correct |
10 |
Correct |
2 ms |
340 KB |
Output is correct |
11 |
Correct |
2 ms |
340 KB |
Output is correct |
12 |
Correct |
2 ms |
340 KB |
Output is correct |
13 |
Correct |
3 ms |
340 KB |
Output is correct |
14 |
Correct |
2 ms |
340 KB |
Output is correct |
15 |
Correct |
2 ms |
328 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
384 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
56 ms |
368 KB |
Output is correct |
22 |
Correct |
54 ms |
340 KB |
Output is correct |
23 |
Correct |
48 ms |
328 KB |
Output is correct |
24 |
Correct |
54 ms |
340 KB |
Output is correct |
25 |
Correct |
55 ms |
340 KB |
Output is correct |
26 |
Correct |
124 ms |
340 KB |
Output is correct |
27 |
Correct |
124 ms |
340 KB |
Output is correct |
28 |
Correct |
120 ms |
368 KB |
Output is correct |
29 |
Correct |
120 ms |
372 KB |
Output is correct |
30 |
Correct |
2 ms |
340 KB |
Output is correct |
31 |
Correct |
3 ms |
340 KB |
Output is correct |
32 |
Correct |
3 ms |
340 KB |
Output is correct |
33 |
Correct |
2 ms |
328 KB |
Output is correct |
34 |
Correct |
2 ms |
340 KB |
Output is correct |
35 |
Correct |
3 ms |
340 KB |
Output is correct |
36 |
Correct |
2 ms |
340 KB |
Output is correct |
37 |
Correct |
2 ms |
340 KB |
Output is correct |
38 |
Correct |
2 ms |
340 KB |
Output is correct |
39 |
Correct |
2 ms |
340 KB |
Output is correct |
40 |
Correct |
2 ms |
340 KB |
Output is correct |
41 |
Correct |
2 ms |
340 KB |
Output is correct |
42 |
Correct |
2 ms |
340 KB |
Output is correct |
43 |
Correct |
2 ms |
340 KB |
Output is correct |
44 |
Correct |
4 ms |
340 KB |
Output is correct |
45 |
Correct |
5 ms |
328 KB |
Output is correct |
46 |
Correct |
4 ms |
340 KB |
Output is correct |
47 |
Correct |
4 ms |
340 KB |
Output is correct |
48 |
Correct |
4 ms |
340 KB |
Output is correct |
49 |
Correct |
2 ms |
340 KB |
Output is correct |
50 |
Correct |
2 ms |
320 KB |
Output is correct |
51 |
Correct |
2 ms |
340 KB |
Output is correct |
52 |
Correct |
2 ms |
320 KB |
Output is correct |
53 |
Correct |
2 ms |
340 KB |
Output is correct |
54 |
Correct |
1 ms |
320 KB |
Output is correct |
55 |
Correct |
1 ms |
320 KB |
Output is correct |
56 |
Correct |
1 ms |
340 KB |
Output is correct |
57 |
Correct |
1 ms |
340 KB |
Output is correct |
58 |
Correct |
2 ms |
340 KB |
Output is correct |
59 |
Correct |
208 ms |
460 KB |
Output is correct |
60 |
Correct |
167 ms |
372 KB |
Output is correct |
61 |
Correct |
158 ms |
372 KB |
Output is correct |
62 |
Correct |
191 ms |
376 KB |
Output is correct |
63 |
Correct |
181 ms |
332 KB |
Output is correct |
64 |
Correct |
439 ms |
376 KB |
Output is correct |
65 |
Correct |
458 ms |
340 KB |
Output is correct |
66 |
Correct |
449 ms |
372 KB |
Output is correct |
67 |
Correct |
477 ms |
376 KB |
Output is correct |
68 |
Correct |
435 ms |
376 KB |
Output is correct |
69 |
Correct |
163 ms |
376 KB |
Output is correct |
70 |
Correct |
163 ms |
340 KB |
Output is correct |
71 |
Correct |
161 ms |
380 KB |
Output is correct |
72 |
Correct |
175 ms |
372 KB |
Output is correct |
73 |
Correct |
173 ms |
376 KB |
Output is correct |
74 |
Correct |
24 ms |
396 KB |
Output is correct |
75 |
Correct |
23 ms |
396 KB |
Output is correct |
76 |
Correct |
24 ms |
392 KB |
Output is correct |
77 |
Correct |
25 ms |
340 KB |
Output is correct |
78 |
Correct |
25 ms |
340 KB |
Output is correct |