#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,bmi,sse,sse2,sse3,sse4")
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
const int N = 3005;
const int oo = 1e18 + 7, mod = 1e9 + 7;
int n, a[N], b[N];
int dp[N][N];
vector<int> vc;
int le[N], ri[N];
int prep[N][N];
int inv[N];
int binpw(int base, int pw){
int ans = 1;
while(pw){
if(pw & 1) ans = (ans * base) % mod;
base = (base * base) % mod;
pw >>= 1;
}
return ans;
}
void pre(int x, int ind){
if(!inv[0]){
inv[0] = 1;
for(int i = 1; i <= n; i++){
inv[i] = binpw(i, mod - 2) % mod;
}
}
int ans = 1;
prep[ind][0] = 1;
for(int i = 1; i <= min(x, n); i++){
ans = (ans * (x - i + 1)) % mod;
ans = (ans * inv[i]) % mod;
prep[ind][i] = ans;
}
}
int c[N][N];
int pref[N][N];
int precal[N][N];
void pr(){
c[0][0] = 1;
for(int i = 1; i <= n; i++){
c[i][0] = 1;
for(int j = 1; j <= i; j++) c[i][j] = (c[i - 1][j] + c[i - 1][j - 1]) % mod;
}
for(int j = 1; j < vc.size(); j++){
for(int cnt = 2; cnt <= n; cnt++){
for(int temp = 2; temp <= cnt; temp++){
precal[j][cnt] = (precal[j][cnt] + c[cnt - 2][temp - 2] * prep[j][temp]) % mod;
}
}
}
}
void process(){
cin >> n;
for(int i = 1; i <= n; i++){
cin >> a[i] >> b[i];
a[i]--;
vc.pb(a[i]), vc.pb(b[i]);
}
sort(vc.begin(), vc.end());
vc.resize(unique(vc.begin(), vc.end()) - vc.begin());
for(int i = 1; i < vc.size(); i++) pre(vc[i] - vc[i - 1], i);
pr();
for(int i = 1; i <= n; i++){
le[i] = lower_bound(vc.begin(), vc.end(), a[i]) - vc.begin();
le[i]++;
ri[i] = lower_bound(vc.begin(), vc.end(), b[i]) - vc.begin();
//cout << i << " " << le[i] << " " << ri[i] << "\n";
}
dp[0][0] = pref[0][0] = 1;
for(int j = 1; j < vc.size(); j++) dp[0][j] = pref[0][j] = 1;
for(int i = 1; i <= n; i++){
dp[i][0] = pref[i][0] = 1;
for(int j = 1; j < vc.size(); j++){
if(le[i] > j || ri[i] < j){
//pref[i][j] = pref[i - 1][j];
continue;
}
dp[i][j] = (pref[i - 1][j - 1] * prep[j][1]) % mod;
//dp[i][j] = dp[i - 1][j];
int sum = 0, cnt = 1;
for(int k = i - 1; k >= 1; k--){
//if(le[k] > j || ri[k] < j) break;
if(le[k] <= j && ri[k] >= j){
cnt++;
//sum = (sum + pref[j][cnt]) % mod;
int sum2 = 0;
/*
for(int temp = 2; temp <= cnt; temp++){
sum2 = (sum2 + c[cnt - 2][temp - 2] * prep[j][temp]) % mod;
}
dp[i][j] = (dp[i][j] + pref[k - 1][j - 1] * sum2) % mod;*/
dp[i][j] = (dp[i][j] + pref[k - 1][j - 1] * precal[j][cnt]) % mod;
//dp[i][j] = (dp[i][j] + (pref[k - 1][j - 1] * sum)) % mod;
//dp[i][j] += dp[i - 1][j - 1] * prep;
}
}
//pref[i][j] += pref[i - 1][j];
}
for(int j = 1; j < vc.size(); j++){
pref[i][j] = (pref[i - 1][j] + pref[i][j - 1] - pref[i - 1][j - 1] + dp[i][j] + 3 * mod) % mod;
}
}
for(int i = 0; i <= n; i++){
//for(int j = 0; j < vc.size(); j++) cout << i << " " << j << " " << pref[i][j] << "\n";
}
cout << (pref[n][vc.size() - 1] + mod - 1) % mod << "\n";
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
process();
}
Compilation message
boat.cpp: In function 'void pr()':
boat.cpp:69:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
69 | for(int j = 1; j < vc.size(); j++){
| ~~^~~~~~~~~~~
boat.cpp: In function 'void process()':
boat.cpp:87:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
87 | for(int i = 1; i < vc.size(); i++) pre(vc[i] - vc[i - 1], i);
| ~~^~~~~~~~~~~
boat.cpp:96:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
96 | for(int j = 1; j < vc.size(); j++) dp[0][j] = pref[0][j] = 1;
| ~~^~~~~~~~~~~
boat.cpp:99:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
99 | for(int j = 1; j < vc.size(); j++){
| ~~^~~~~~~~~~~
boat.cpp:112:10: warning: unused variable 'sum2' [-Wunused-variable]
112 | int sum2 = 0;
| ^~~~
boat.cpp:106:8: warning: unused variable 'sum' [-Wunused-variable]
106 | int sum = 0, cnt = 1;
| ^~~
boat.cpp:125:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
125 | for(int j = 1; j < vc.size(); j++){
| ~~^~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
526 ms |
26756 KB |
Output is correct |
2 |
Correct |
528 ms |
26808 KB |
Output is correct |
3 |
Correct |
518 ms |
26896 KB |
Output is correct |
4 |
Correct |
540 ms |
26748 KB |
Output is correct |
5 |
Correct |
552 ms |
26812 KB |
Output is correct |
6 |
Correct |
531 ms |
26860 KB |
Output is correct |
7 |
Correct |
563 ms |
26760 KB |
Output is correct |
8 |
Correct |
527 ms |
26736 KB |
Output is correct |
9 |
Correct |
509 ms |
26696 KB |
Output is correct |
10 |
Correct |
515 ms |
26864 KB |
Output is correct |
11 |
Correct |
523 ms |
26656 KB |
Output is correct |
12 |
Correct |
527 ms |
26840 KB |
Output is correct |
13 |
Correct |
516 ms |
26832 KB |
Output is correct |
14 |
Correct |
512 ms |
26780 KB |
Output is correct |
15 |
Correct |
507 ms |
26880 KB |
Output is correct |
16 |
Correct |
97 ms |
10796 KB |
Output is correct |
17 |
Correct |
104 ms |
11020 KB |
Output is correct |
18 |
Correct |
95 ms |
10920 KB |
Output is correct |
19 |
Correct |
101 ms |
11036 KB |
Output is correct |
20 |
Correct |
97 ms |
10896 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
526 ms |
26756 KB |
Output is correct |
2 |
Correct |
528 ms |
26808 KB |
Output is correct |
3 |
Correct |
518 ms |
26896 KB |
Output is correct |
4 |
Correct |
540 ms |
26748 KB |
Output is correct |
5 |
Correct |
552 ms |
26812 KB |
Output is correct |
6 |
Correct |
531 ms |
26860 KB |
Output is correct |
7 |
Correct |
563 ms |
26760 KB |
Output is correct |
8 |
Correct |
527 ms |
26736 KB |
Output is correct |
9 |
Correct |
509 ms |
26696 KB |
Output is correct |
10 |
Correct |
515 ms |
26864 KB |
Output is correct |
11 |
Correct |
523 ms |
26656 KB |
Output is correct |
12 |
Correct |
527 ms |
26840 KB |
Output is correct |
13 |
Correct |
516 ms |
26832 KB |
Output is correct |
14 |
Correct |
512 ms |
26780 KB |
Output is correct |
15 |
Correct |
507 ms |
26880 KB |
Output is correct |
16 |
Correct |
97 ms |
10796 KB |
Output is correct |
17 |
Correct |
104 ms |
11020 KB |
Output is correct |
18 |
Correct |
95 ms |
10920 KB |
Output is correct |
19 |
Correct |
101 ms |
11036 KB |
Output is correct |
20 |
Correct |
97 ms |
10896 KB |
Output is correct |
21 |
Correct |
574 ms |
24160 KB |
Output is correct |
22 |
Correct |
573 ms |
24476 KB |
Output is correct |
23 |
Correct |
553 ms |
24128 KB |
Output is correct |
24 |
Correct |
569 ms |
24048 KB |
Output is correct |
25 |
Correct |
567 ms |
24088 KB |
Output is correct |
26 |
Correct |
699 ms |
23968 KB |
Output is correct |
27 |
Correct |
718 ms |
24332 KB |
Output is correct |
28 |
Correct |
704 ms |
24096 KB |
Output is correct |
29 |
Correct |
679 ms |
23944 KB |
Output is correct |
30 |
Correct |
516 ms |
26536 KB |
Output is correct |
31 |
Correct |
515 ms |
26672 KB |
Output is correct |
32 |
Correct |
512 ms |
26580 KB |
Output is correct |
33 |
Correct |
517 ms |
26664 KB |
Output is correct |
34 |
Correct |
501 ms |
26568 KB |
Output is correct |
35 |
Correct |
511 ms |
26444 KB |
Output is correct |
36 |
Correct |
513 ms |
26700 KB |
Output is correct |
37 |
Correct |
508 ms |
26528 KB |
Output is correct |
38 |
Correct |
514 ms |
26448 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
3788 KB |
Output is correct |
2 |
Correct |
7 ms |
3796 KB |
Output is correct |
3 |
Correct |
8 ms |
3708 KB |
Output is correct |
4 |
Correct |
7 ms |
3800 KB |
Output is correct |
5 |
Correct |
7 ms |
3788 KB |
Output is correct |
6 |
Correct |
8 ms |
3796 KB |
Output is correct |
7 |
Correct |
8 ms |
3812 KB |
Output is correct |
8 |
Correct |
8 ms |
3796 KB |
Output is correct |
9 |
Correct |
8 ms |
3752 KB |
Output is correct |
10 |
Correct |
8 ms |
3796 KB |
Output is correct |
11 |
Correct |
8 ms |
3796 KB |
Output is correct |
12 |
Correct |
7 ms |
3796 KB |
Output is correct |
13 |
Correct |
7 ms |
3796 KB |
Output is correct |
14 |
Correct |
7 ms |
3792 KB |
Output is correct |
15 |
Correct |
7 ms |
3796 KB |
Output is correct |
16 |
Correct |
5 ms |
2772 KB |
Output is correct |
17 |
Correct |
4 ms |
2772 KB |
Output is correct |
18 |
Correct |
4 ms |
2772 KB |
Output is correct |
19 |
Correct |
5 ms |
2772 KB |
Output is correct |
20 |
Correct |
4 ms |
2772 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
526 ms |
26756 KB |
Output is correct |
2 |
Correct |
528 ms |
26808 KB |
Output is correct |
3 |
Correct |
518 ms |
26896 KB |
Output is correct |
4 |
Correct |
540 ms |
26748 KB |
Output is correct |
5 |
Correct |
552 ms |
26812 KB |
Output is correct |
6 |
Correct |
531 ms |
26860 KB |
Output is correct |
7 |
Correct |
563 ms |
26760 KB |
Output is correct |
8 |
Correct |
527 ms |
26736 KB |
Output is correct |
9 |
Correct |
509 ms |
26696 KB |
Output is correct |
10 |
Correct |
515 ms |
26864 KB |
Output is correct |
11 |
Correct |
523 ms |
26656 KB |
Output is correct |
12 |
Correct |
527 ms |
26840 KB |
Output is correct |
13 |
Correct |
516 ms |
26832 KB |
Output is correct |
14 |
Correct |
512 ms |
26780 KB |
Output is correct |
15 |
Correct |
507 ms |
26880 KB |
Output is correct |
16 |
Correct |
97 ms |
10796 KB |
Output is correct |
17 |
Correct |
104 ms |
11020 KB |
Output is correct |
18 |
Correct |
95 ms |
10920 KB |
Output is correct |
19 |
Correct |
101 ms |
11036 KB |
Output is correct |
20 |
Correct |
97 ms |
10896 KB |
Output is correct |
21 |
Correct |
574 ms |
24160 KB |
Output is correct |
22 |
Correct |
573 ms |
24476 KB |
Output is correct |
23 |
Correct |
553 ms |
24128 KB |
Output is correct |
24 |
Correct |
569 ms |
24048 KB |
Output is correct |
25 |
Correct |
567 ms |
24088 KB |
Output is correct |
26 |
Correct |
699 ms |
23968 KB |
Output is correct |
27 |
Correct |
718 ms |
24332 KB |
Output is correct |
28 |
Correct |
704 ms |
24096 KB |
Output is correct |
29 |
Correct |
679 ms |
23944 KB |
Output is correct |
30 |
Correct |
516 ms |
26536 KB |
Output is correct |
31 |
Correct |
515 ms |
26672 KB |
Output is correct |
32 |
Correct |
512 ms |
26580 KB |
Output is correct |
33 |
Correct |
517 ms |
26664 KB |
Output is correct |
34 |
Correct |
501 ms |
26568 KB |
Output is correct |
35 |
Correct |
511 ms |
26444 KB |
Output is correct |
36 |
Correct |
513 ms |
26700 KB |
Output is correct |
37 |
Correct |
508 ms |
26528 KB |
Output is correct |
38 |
Correct |
514 ms |
26448 KB |
Output is correct |
39 |
Correct |
7 ms |
3788 KB |
Output is correct |
40 |
Correct |
7 ms |
3796 KB |
Output is correct |
41 |
Correct |
8 ms |
3708 KB |
Output is correct |
42 |
Correct |
7 ms |
3800 KB |
Output is correct |
43 |
Correct |
7 ms |
3788 KB |
Output is correct |
44 |
Correct |
8 ms |
3796 KB |
Output is correct |
45 |
Correct |
8 ms |
3812 KB |
Output is correct |
46 |
Correct |
8 ms |
3796 KB |
Output is correct |
47 |
Correct |
8 ms |
3752 KB |
Output is correct |
48 |
Correct |
8 ms |
3796 KB |
Output is correct |
49 |
Correct |
8 ms |
3796 KB |
Output is correct |
50 |
Correct |
7 ms |
3796 KB |
Output is correct |
51 |
Correct |
7 ms |
3796 KB |
Output is correct |
52 |
Correct |
7 ms |
3792 KB |
Output is correct |
53 |
Correct |
7 ms |
3796 KB |
Output is correct |
54 |
Correct |
5 ms |
2772 KB |
Output is correct |
55 |
Correct |
4 ms |
2772 KB |
Output is correct |
56 |
Correct |
4 ms |
2772 KB |
Output is correct |
57 |
Correct |
5 ms |
2772 KB |
Output is correct |
58 |
Correct |
4 ms |
2772 KB |
Output is correct |
59 |
Correct |
631 ms |
29712 KB |
Output is correct |
60 |
Correct |
618 ms |
29780 KB |
Output is correct |
61 |
Correct |
606 ms |
29584 KB |
Output is correct |
62 |
Correct |
649 ms |
29632 KB |
Output is correct |
63 |
Correct |
656 ms |
29528 KB |
Output is correct |
64 |
Correct |
812 ms |
30300 KB |
Output is correct |
65 |
Correct |
798 ms |
30268 KB |
Output is correct |
66 |
Correct |
799 ms |
30172 KB |
Output is correct |
67 |
Correct |
827 ms |
30100 KB |
Output is correct |
68 |
Correct |
807 ms |
30208 KB |
Output is correct |
69 |
Correct |
612 ms |
29640 KB |
Output is correct |
70 |
Correct |
606 ms |
29644 KB |
Output is correct |
71 |
Correct |
608 ms |
29628 KB |
Output is correct |
72 |
Correct |
626 ms |
29568 KB |
Output is correct |
73 |
Correct |
626 ms |
29636 KB |
Output is correct |
74 |
Correct |
130 ms |
11084 KB |
Output is correct |
75 |
Correct |
120 ms |
11244 KB |
Output is correct |
76 |
Correct |
120 ms |
11212 KB |
Output is correct |
77 |
Correct |
141 ms |
11212 KB |
Output is correct |
78 |
Correct |
132 ms |
11080 KB |
Output is correct |