#include <bits/stdc++.h>
using namespace std;
int N;
pair<int,int> lst[510];
int a, b;
long long int mod = 1'000'000'007;
long long int p[510];
long long int fact[510];
vector<int> de;
vector<int> bat[1100];
map<int,int> mep;
long long int expo(long long int x, long long int b, long long int mul){
if(mul == 0) return x;
if(mul % 2 == 1){
return expo(x * b % mod, b * b % mod, mul / 2);
}
else{
return expo(x, b * b % mod, mul / 2);
}
}
int main(){
scanf(" %d",&N);
for(int i = 1; i <= N; i++){
scanf(" %d",&a);
scanf(" %d",&b);
lst[i] = {a,b};
de.push_back(a);
de.push_back(b + 1);
p[i] = 0;
}
p[N + 1] = 0;
p[0] = 1;
fact[0] = 1;
for(int i = 1; i < 510; i++){
fact[i] = fact[i - 1] * i % mod;
}
sort(de.begin(),de.end());
de.resize(unique(de.begin(),de.end()) - de.begin());
for(int i = 0; i < de.size(); i++){
mep[de[i]] = i;
}
for(int i = 1; i <= N; i++){
for(int j = 0; j < de.size(); j++){
if(lst[i].first <= de[j] && de[j] <= lst[i].second){
bat[j].push_back(i);
}
}
}
for(int i = 0; i < de.size() - 1; i++){
long long int mul[510];
int c = de[i + 1] - de[i];
mul[0] = c;
for(int i = 1; i < 509; i++){
mul[i] = mul[i - 1] * (i + c) % mod;
}
for(int i = 0; i < 509; i++){
mul[i] = expo(mul[i], fact[i + 1], mod - 2);
//printf("%lld ",mul[i]);
}
vector<int> v = {0};
long long int pst[510];
for(int i = 0; i <= 501; i++){
pst[i] = 0;
}
for(int j = 0; j < bat[i].size(); j++){
v.push_back(bat[i][j]);
long long int sum = 0;
for(int k = 0; k < v.size() - 1; k++){
int ni = v.size();
for(int i = v[ni - 2 - k]; i <= v[ni - 1 - k] - 1; i++){
sum = (sum + p[i] * mul[k]) % mod;
}
}
pst[bat[i][j]] = sum;
}
for(int i = 0; i <= 501; i++){
p[i] = (p[i] + pst[i]) % mod;
}
}
long long int ans = 0;
for(int i = 1; i <= N; i++){
ans = (ans + p[i]) % mod;
}
printf("%lld",ans);
}
/*
3
1 2
2 4
2 4
2
1 2
2 4
3
2 2
4 4
4 4
*/
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:50:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
50 | for(int i = 0; i < de.size(); i++){
| ~~^~~~~~~~~~~
boat.cpp:55:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
55 | for(int j = 0; j < de.size(); j++){
| ~~^~~~~~~~~~~
boat.cpp:62:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
62 | for(int i = 0; i < de.size() - 1; i++){
| ~~^~~~~~~~~~~~~~~
boat.cpp:85:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
85 | for(int j = 0; j < bat[i].size(); j++){
| ~~^~~~~~~~~~~~~~~
boat.cpp:89:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
89 | for(int k = 0; k < v.size() - 1; k++){
| ~~^~~~~~~~~~~~~~
boat.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
26 | scanf(" %d",&N);
| ~~~~~^~~~~~~~~~
boat.cpp:29:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
29 | scanf(" %d",&a);
| ~~~~~^~~~~~~~~~
boat.cpp:30:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
30 | scanf(" %d",&b);
| ~~~~~^~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
199 ms |
772 KB |
Output is correct |
2 |
Correct |
198 ms |
344 KB |
Output is correct |
3 |
Correct |
198 ms |
524 KB |
Output is correct |
4 |
Correct |
199 ms |
348 KB |
Output is correct |
5 |
Correct |
198 ms |
520 KB |
Output is correct |
6 |
Correct |
199 ms |
348 KB |
Output is correct |
7 |
Correct |
198 ms |
348 KB |
Output is correct |
8 |
Correct |
199 ms |
540 KB |
Output is correct |
9 |
Correct |
198 ms |
348 KB |
Output is correct |
10 |
Correct |
199 ms |
520 KB |
Output is correct |
11 |
Correct |
199 ms |
592 KB |
Output is correct |
12 |
Correct |
199 ms |
348 KB |
Output is correct |
13 |
Correct |
198 ms |
348 KB |
Output is correct |
14 |
Correct |
199 ms |
520 KB |
Output is correct |
15 |
Correct |
199 ms |
344 KB |
Output is correct |
16 |
Correct |
36 ms |
348 KB |
Output is correct |
17 |
Correct |
38 ms |
348 KB |
Output is correct |
18 |
Correct |
37 ms |
344 KB |
Output is correct |
19 |
Correct |
39 ms |
348 KB |
Output is correct |
20 |
Correct |
37 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
199 ms |
772 KB |
Output is correct |
2 |
Correct |
198 ms |
344 KB |
Output is correct |
3 |
Correct |
198 ms |
524 KB |
Output is correct |
4 |
Correct |
199 ms |
348 KB |
Output is correct |
5 |
Correct |
198 ms |
520 KB |
Output is correct |
6 |
Correct |
199 ms |
348 KB |
Output is correct |
7 |
Correct |
198 ms |
348 KB |
Output is correct |
8 |
Correct |
199 ms |
540 KB |
Output is correct |
9 |
Correct |
198 ms |
348 KB |
Output is correct |
10 |
Correct |
199 ms |
520 KB |
Output is correct |
11 |
Correct |
199 ms |
592 KB |
Output is correct |
12 |
Correct |
199 ms |
348 KB |
Output is correct |
13 |
Correct |
198 ms |
348 KB |
Output is correct |
14 |
Correct |
199 ms |
520 KB |
Output is correct |
15 |
Correct |
199 ms |
344 KB |
Output is correct |
16 |
Correct |
36 ms |
348 KB |
Output is correct |
17 |
Correct |
38 ms |
348 KB |
Output is correct |
18 |
Correct |
37 ms |
344 KB |
Output is correct |
19 |
Correct |
39 ms |
348 KB |
Output is correct |
20 |
Correct |
37 ms |
348 KB |
Output is correct |
21 |
Correct |
407 ms |
1368 KB |
Output is correct |
22 |
Correct |
398 ms |
1732 KB |
Output is correct |
23 |
Correct |
382 ms |
1368 KB |
Output is correct |
24 |
Correct |
398 ms |
1452 KB |
Output is correct |
25 |
Correct |
394 ms |
1372 KB |
Output is correct |
26 |
Correct |
509 ms |
1708 KB |
Output is correct |
27 |
Correct |
525 ms |
1876 KB |
Output is correct |
28 |
Correct |
511 ms |
1628 KB |
Output is correct |
29 |
Correct |
510 ms |
1716 KB |
Output is correct |
30 |
Correct |
199 ms |
548 KB |
Output is correct |
31 |
Correct |
200 ms |
552 KB |
Output is correct |
32 |
Correct |
198 ms |
348 KB |
Output is correct |
33 |
Correct |
200 ms |
348 KB |
Output is correct |
34 |
Correct |
199 ms |
344 KB |
Output is correct |
35 |
Correct |
199 ms |
348 KB |
Output is correct |
36 |
Correct |
199 ms |
344 KB |
Output is correct |
37 |
Correct |
199 ms |
568 KB |
Output is correct |
38 |
Correct |
198 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
42 ms |
348 KB |
Output is correct |
2 |
Correct |
42 ms |
348 KB |
Output is correct |
3 |
Correct |
42 ms |
344 KB |
Output is correct |
4 |
Correct |
42 ms |
344 KB |
Output is correct |
5 |
Correct |
42 ms |
348 KB |
Output is correct |
6 |
Correct |
44 ms |
348 KB |
Output is correct |
7 |
Correct |
44 ms |
348 KB |
Output is correct |
8 |
Correct |
44 ms |
348 KB |
Output is correct |
9 |
Correct |
44 ms |
472 KB |
Output is correct |
10 |
Correct |
44 ms |
600 KB |
Output is correct |
11 |
Correct |
43 ms |
520 KB |
Output is correct |
12 |
Correct |
42 ms |
512 KB |
Output is correct |
13 |
Correct |
42 ms |
348 KB |
Output is correct |
14 |
Correct |
42 ms |
344 KB |
Output is correct |
15 |
Correct |
42 ms |
344 KB |
Output is correct |
16 |
Correct |
25 ms |
520 KB |
Output is correct |
17 |
Correct |
24 ms |
348 KB |
Output is correct |
18 |
Correct |
24 ms |
520 KB |
Output is correct |
19 |
Correct |
24 ms |
344 KB |
Output is correct |
20 |
Correct |
23 ms |
344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
199 ms |
772 KB |
Output is correct |
2 |
Correct |
198 ms |
344 KB |
Output is correct |
3 |
Correct |
198 ms |
524 KB |
Output is correct |
4 |
Correct |
199 ms |
348 KB |
Output is correct |
5 |
Correct |
198 ms |
520 KB |
Output is correct |
6 |
Correct |
199 ms |
348 KB |
Output is correct |
7 |
Correct |
198 ms |
348 KB |
Output is correct |
8 |
Correct |
199 ms |
540 KB |
Output is correct |
9 |
Correct |
198 ms |
348 KB |
Output is correct |
10 |
Correct |
199 ms |
520 KB |
Output is correct |
11 |
Correct |
199 ms |
592 KB |
Output is correct |
12 |
Correct |
199 ms |
348 KB |
Output is correct |
13 |
Correct |
198 ms |
348 KB |
Output is correct |
14 |
Correct |
199 ms |
520 KB |
Output is correct |
15 |
Correct |
199 ms |
344 KB |
Output is correct |
16 |
Correct |
36 ms |
348 KB |
Output is correct |
17 |
Correct |
38 ms |
348 KB |
Output is correct |
18 |
Correct |
37 ms |
344 KB |
Output is correct |
19 |
Correct |
39 ms |
348 KB |
Output is correct |
20 |
Correct |
37 ms |
348 KB |
Output is correct |
21 |
Correct |
407 ms |
1368 KB |
Output is correct |
22 |
Correct |
398 ms |
1732 KB |
Output is correct |
23 |
Correct |
382 ms |
1368 KB |
Output is correct |
24 |
Correct |
398 ms |
1452 KB |
Output is correct |
25 |
Correct |
394 ms |
1372 KB |
Output is correct |
26 |
Correct |
509 ms |
1708 KB |
Output is correct |
27 |
Correct |
525 ms |
1876 KB |
Output is correct |
28 |
Correct |
511 ms |
1628 KB |
Output is correct |
29 |
Correct |
510 ms |
1716 KB |
Output is correct |
30 |
Correct |
199 ms |
548 KB |
Output is correct |
31 |
Correct |
200 ms |
552 KB |
Output is correct |
32 |
Correct |
198 ms |
348 KB |
Output is correct |
33 |
Correct |
200 ms |
348 KB |
Output is correct |
34 |
Correct |
199 ms |
344 KB |
Output is correct |
35 |
Correct |
199 ms |
348 KB |
Output is correct |
36 |
Correct |
199 ms |
344 KB |
Output is correct |
37 |
Correct |
199 ms |
568 KB |
Output is correct |
38 |
Correct |
198 ms |
348 KB |
Output is correct |
39 |
Correct |
42 ms |
348 KB |
Output is correct |
40 |
Correct |
42 ms |
348 KB |
Output is correct |
41 |
Correct |
42 ms |
344 KB |
Output is correct |
42 |
Correct |
42 ms |
344 KB |
Output is correct |
43 |
Correct |
42 ms |
348 KB |
Output is correct |
44 |
Correct |
44 ms |
348 KB |
Output is correct |
45 |
Correct |
44 ms |
348 KB |
Output is correct |
46 |
Correct |
44 ms |
348 KB |
Output is correct |
47 |
Correct |
44 ms |
472 KB |
Output is correct |
48 |
Correct |
44 ms |
600 KB |
Output is correct |
49 |
Correct |
43 ms |
520 KB |
Output is correct |
50 |
Correct |
42 ms |
512 KB |
Output is correct |
51 |
Correct |
42 ms |
348 KB |
Output is correct |
52 |
Correct |
42 ms |
344 KB |
Output is correct |
53 |
Correct |
42 ms |
344 KB |
Output is correct |
54 |
Correct |
25 ms |
520 KB |
Output is correct |
55 |
Correct |
24 ms |
348 KB |
Output is correct |
56 |
Correct |
24 ms |
520 KB |
Output is correct |
57 |
Correct |
24 ms |
344 KB |
Output is correct |
58 |
Correct |
23 ms |
344 KB |
Output is correct |
59 |
Correct |
506 ms |
1536 KB |
Output is correct |
60 |
Correct |
491 ms |
1624 KB |
Output is correct |
61 |
Correct |
473 ms |
1620 KB |
Output is correct |
62 |
Correct |
506 ms |
1628 KB |
Output is correct |
63 |
Correct |
499 ms |
1372 KB |
Output is correct |
64 |
Correct |
720 ms |
1884 KB |
Output is correct |
65 |
Correct |
725 ms |
1892 KB |
Output is correct |
66 |
Correct |
721 ms |
1884 KB |
Output is correct |
67 |
Correct |
722 ms |
1880 KB |
Output is correct |
68 |
Correct |
718 ms |
1880 KB |
Output is correct |
69 |
Correct |
473 ms |
1400 KB |
Output is correct |
70 |
Correct |
465 ms |
1616 KB |
Output is correct |
71 |
Correct |
463 ms |
1396 KB |
Output is correct |
72 |
Correct |
474 ms |
1408 KB |
Output is correct |
73 |
Correct |
481 ms |
1396 KB |
Output is correct |
74 |
Correct |
84 ms |
604 KB |
Output is correct |
75 |
Correct |
82 ms |
604 KB |
Output is correct |
76 |
Correct |
86 ms |
676 KB |
Output is correct |
77 |
Correct |
84 ms |
604 KB |
Output is correct |
78 |
Correct |
85 ms |
604 KB |
Output is correct |