#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define fi first
#define se second
#define mp make_pair
#define fastIO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
const int N = 505;
const int M = N * 4;
const int MOD = (int)1e9 + 7;
int L[N], R[N];
int C[M][N];
int I[N][N];
int fin[M][N];
int powr(int n, int k){
if(k == 0) return 1;
int p = powr(n, k / 2);
p = (p * 1ll * p) % MOD;
if(k % 2 == 1) p = (p * 1ll * n) % MOD;
return p;
}
void add(int &a, int b){
a += b;
if(a >= MOD) a -= MOD;
else if(a < 0) a += MOD;
}
int dp[N][M];
int dif[N];
int main(){
fastIO;
//freopen("in.txt","r",stdin);
int n;
cin >> n;
vector<int> pp;
for(int i = 1; i <= n; i ++ ){
cin >> L[i] >> R[i];
pp.push_back(L[i]);
pp.push_back(R[i]);
}
sort(pp.begin(), pp.end());
pp.resize(unique(pp.begin(), pp.end()) - pp.begin());
vector<pii> segm;
for(int i = 0 ; i < pp.size(); i ++ ){
segm.push_back(mp(pp[i], pp[i]));
if(i + 1 < pp.size() && pp[i] + 1 <= pp[i + 1] - 1){
segm.push_back(mp(pp[i] + 1, pp[i + 1] - 1));
}
}
int m = segm.size();
for(int i = 0; i < N ;i ++ ){
I[i][0] = 1;
}
for(int k = 1; k < N ; k ++ ){
for(int i = 1; i < N ; i ++ ){
add(I[i][k], I[i-1][k]);
add(I[i][k], I[i-1][k-1]);
}
}
int sz;
int P, Q;
int inv;
int cum;
for(int i = 0 ; i < m ; i ++ ){
sz = segm[i].se - segm[i].fi + 1;
P = Q = 1;
for(int j = 1; j <= n; j ++ ){
if(j > sz) break;
P = (P * 1ll * (sz - j + 1)) % MOD;
Q = (Q * 1ll * j) % MOD;
inv = powr(Q, MOD - 2);
C[i][j] = (P * 1ll * inv) % MOD;
}
if(sz == 1){
for(int j = 1; j <= n; j ++ ){
fin[i][j] = j;
}
}
else{
for(int j = 1; j <= n; j ++ ){
for(int v = 1; v <= j; v ++ ){
add(fin[i][j], (C[i][v] * 1ll * I[j][v]) % MOD);
}
}
}
for(int j = n; j >= 1; j -- ){
add(fin[i][j], -fin[i][j-1]);
}
}
int tl, tr;
int mm;
int side;
int res = 0;
for(int i = 1; i <= n; i ++ ){
for(int j = 0 ; j < m ; j ++ ){
tl = segm[j].fi;
tr = segm[j].se;
if(L[i] <= tl && tr <= R[i]){
if(tl == tr){
add(dp[i][j], +1);
if(j > 0){
for(int v = i - 1; v >= 1; v -- ){
add(dp[i][j], dp[v][j-1]);
}
}
}
else{
mm = 0;
for(int v = i; v >= 1; v -- ){
if(L[v] <= tl && tr <= R[v]) mm ++ ;
side = 0;
if(j > 0) add(side, dp[v - 1][j - 1]);
if(v == 1) add(side, 1);
add(dp[i][j], (side * 1ll * fin[j][mm]) % MOD);
}
}
}
add(res, dp[i][j]);
if(j)
add(dp[i][j], dp[i][j-1]);
}
}
cout << res << "\n";
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:55:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
55 | for(int i = 0 ; i < pp.size(); i ++ ){
| ~~^~~~~~~~~~~
boat.cpp:57:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
57 | if(i + 1 < pp.size() && pp[i] + 1 <= pp[i + 1] - 1){
| ~~~~~~^~~~~~~~~~~
boat.cpp:74:9: warning: unused variable 'cum' [-Wunused-variable]
74 | int cum;
| ^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
500 ms |
9192 KB |
Output is correct |
2 |
Correct |
469 ms |
9112 KB |
Output is correct |
3 |
Correct |
484 ms |
9340 KB |
Output is correct |
4 |
Correct |
464 ms |
9224 KB |
Output is correct |
5 |
Correct |
481 ms |
9132 KB |
Output is correct |
6 |
Correct |
473 ms |
9124 KB |
Output is correct |
7 |
Correct |
465 ms |
9284 KB |
Output is correct |
8 |
Correct |
456 ms |
9452 KB |
Output is correct |
9 |
Correct |
454 ms |
9152 KB |
Output is correct |
10 |
Correct |
459 ms |
9268 KB |
Output is correct |
11 |
Correct |
460 ms |
9160 KB |
Output is correct |
12 |
Correct |
460 ms |
9312 KB |
Output is correct |
13 |
Correct |
457 ms |
9232 KB |
Output is correct |
14 |
Correct |
457 ms |
9156 KB |
Output is correct |
15 |
Correct |
465 ms |
9324 KB |
Output is correct |
16 |
Correct |
85 ms |
4304 KB |
Output is correct |
17 |
Correct |
90 ms |
4308 KB |
Output is correct |
18 |
Correct |
85 ms |
4344 KB |
Output is correct |
19 |
Correct |
89 ms |
4380 KB |
Output is correct |
20 |
Correct |
91 ms |
4356 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
500 ms |
9192 KB |
Output is correct |
2 |
Correct |
469 ms |
9112 KB |
Output is correct |
3 |
Correct |
484 ms |
9340 KB |
Output is correct |
4 |
Correct |
464 ms |
9224 KB |
Output is correct |
5 |
Correct |
481 ms |
9132 KB |
Output is correct |
6 |
Correct |
473 ms |
9124 KB |
Output is correct |
7 |
Correct |
465 ms |
9284 KB |
Output is correct |
8 |
Correct |
456 ms |
9452 KB |
Output is correct |
9 |
Correct |
454 ms |
9152 KB |
Output is correct |
10 |
Correct |
459 ms |
9268 KB |
Output is correct |
11 |
Correct |
460 ms |
9160 KB |
Output is correct |
12 |
Correct |
460 ms |
9312 KB |
Output is correct |
13 |
Correct |
457 ms |
9232 KB |
Output is correct |
14 |
Correct |
457 ms |
9156 KB |
Output is correct |
15 |
Correct |
465 ms |
9324 KB |
Output is correct |
16 |
Correct |
85 ms |
4304 KB |
Output is correct |
17 |
Correct |
90 ms |
4308 KB |
Output is correct |
18 |
Correct |
85 ms |
4344 KB |
Output is correct |
19 |
Correct |
89 ms |
4380 KB |
Output is correct |
20 |
Correct |
91 ms |
4356 KB |
Output is correct |
21 |
Correct |
681 ms |
11856 KB |
Output is correct |
22 |
Correct |
675 ms |
11808 KB |
Output is correct |
23 |
Correct |
642 ms |
11748 KB |
Output is correct |
24 |
Correct |
686 ms |
12108 KB |
Output is correct |
25 |
Correct |
667 ms |
11716 KB |
Output is correct |
26 |
Correct |
716 ms |
11388 KB |
Output is correct |
27 |
Correct |
751 ms |
11440 KB |
Output is correct |
28 |
Correct |
740 ms |
11604 KB |
Output is correct |
29 |
Correct |
751 ms |
11704 KB |
Output is correct |
30 |
Correct |
553 ms |
12612 KB |
Output is correct |
31 |
Correct |
557 ms |
12468 KB |
Output is correct |
32 |
Correct |
560 ms |
12640 KB |
Output is correct |
33 |
Correct |
573 ms |
12540 KB |
Output is correct |
34 |
Correct |
584 ms |
12492 KB |
Output is correct |
35 |
Correct |
446 ms |
9340 KB |
Output is correct |
36 |
Correct |
435 ms |
9156 KB |
Output is correct |
37 |
Correct |
467 ms |
9236 KB |
Output is correct |
38 |
Correct |
445 ms |
9180 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
19 ms |
3404 KB |
Output is correct |
2 |
Correct |
22 ms |
3456 KB |
Output is correct |
3 |
Correct |
23 ms |
3376 KB |
Output is correct |
4 |
Correct |
19 ms |
3344 KB |
Output is correct |
5 |
Correct |
20 ms |
3428 KB |
Output is correct |
6 |
Correct |
21 ms |
3392 KB |
Output is correct |
7 |
Correct |
21 ms |
3372 KB |
Output is correct |
8 |
Correct |
21 ms |
3444 KB |
Output is correct |
9 |
Correct |
21 ms |
3396 KB |
Output is correct |
10 |
Correct |
21 ms |
3352 KB |
Output is correct |
11 |
Correct |
20 ms |
3388 KB |
Output is correct |
12 |
Correct |
18 ms |
3336 KB |
Output is correct |
13 |
Correct |
18 ms |
3456 KB |
Output is correct |
14 |
Correct |
19 ms |
3424 KB |
Output is correct |
15 |
Correct |
19 ms |
3440 KB |
Output is correct |
16 |
Correct |
9 ms |
2380 KB |
Output is correct |
17 |
Correct |
9 ms |
2444 KB |
Output is correct |
18 |
Correct |
10 ms |
2380 KB |
Output is correct |
19 |
Correct |
9 ms |
2380 KB |
Output is correct |
20 |
Correct |
10 ms |
2380 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
500 ms |
9192 KB |
Output is correct |
2 |
Correct |
469 ms |
9112 KB |
Output is correct |
3 |
Correct |
484 ms |
9340 KB |
Output is correct |
4 |
Correct |
464 ms |
9224 KB |
Output is correct |
5 |
Correct |
481 ms |
9132 KB |
Output is correct |
6 |
Correct |
473 ms |
9124 KB |
Output is correct |
7 |
Correct |
465 ms |
9284 KB |
Output is correct |
8 |
Correct |
456 ms |
9452 KB |
Output is correct |
9 |
Correct |
454 ms |
9152 KB |
Output is correct |
10 |
Correct |
459 ms |
9268 KB |
Output is correct |
11 |
Correct |
460 ms |
9160 KB |
Output is correct |
12 |
Correct |
460 ms |
9312 KB |
Output is correct |
13 |
Correct |
457 ms |
9232 KB |
Output is correct |
14 |
Correct |
457 ms |
9156 KB |
Output is correct |
15 |
Correct |
465 ms |
9324 KB |
Output is correct |
16 |
Correct |
85 ms |
4304 KB |
Output is correct |
17 |
Correct |
90 ms |
4308 KB |
Output is correct |
18 |
Correct |
85 ms |
4344 KB |
Output is correct |
19 |
Correct |
89 ms |
4380 KB |
Output is correct |
20 |
Correct |
91 ms |
4356 KB |
Output is correct |
21 |
Correct |
681 ms |
11856 KB |
Output is correct |
22 |
Correct |
675 ms |
11808 KB |
Output is correct |
23 |
Correct |
642 ms |
11748 KB |
Output is correct |
24 |
Correct |
686 ms |
12108 KB |
Output is correct |
25 |
Correct |
667 ms |
11716 KB |
Output is correct |
26 |
Correct |
716 ms |
11388 KB |
Output is correct |
27 |
Correct |
751 ms |
11440 KB |
Output is correct |
28 |
Correct |
740 ms |
11604 KB |
Output is correct |
29 |
Correct |
751 ms |
11704 KB |
Output is correct |
30 |
Correct |
553 ms |
12612 KB |
Output is correct |
31 |
Correct |
557 ms |
12468 KB |
Output is correct |
32 |
Correct |
560 ms |
12640 KB |
Output is correct |
33 |
Correct |
573 ms |
12540 KB |
Output is correct |
34 |
Correct |
584 ms |
12492 KB |
Output is correct |
35 |
Correct |
446 ms |
9340 KB |
Output is correct |
36 |
Correct |
435 ms |
9156 KB |
Output is correct |
37 |
Correct |
467 ms |
9236 KB |
Output is correct |
38 |
Correct |
445 ms |
9180 KB |
Output is correct |
39 |
Correct |
19 ms |
3404 KB |
Output is correct |
40 |
Correct |
22 ms |
3456 KB |
Output is correct |
41 |
Correct |
23 ms |
3376 KB |
Output is correct |
42 |
Correct |
19 ms |
3344 KB |
Output is correct |
43 |
Correct |
20 ms |
3428 KB |
Output is correct |
44 |
Correct |
21 ms |
3392 KB |
Output is correct |
45 |
Correct |
21 ms |
3372 KB |
Output is correct |
46 |
Correct |
21 ms |
3444 KB |
Output is correct |
47 |
Correct |
21 ms |
3396 KB |
Output is correct |
48 |
Correct |
21 ms |
3352 KB |
Output is correct |
49 |
Correct |
20 ms |
3388 KB |
Output is correct |
50 |
Correct |
18 ms |
3336 KB |
Output is correct |
51 |
Correct |
18 ms |
3456 KB |
Output is correct |
52 |
Correct |
19 ms |
3424 KB |
Output is correct |
53 |
Correct |
19 ms |
3440 KB |
Output is correct |
54 |
Correct |
9 ms |
2380 KB |
Output is correct |
55 |
Correct |
9 ms |
2444 KB |
Output is correct |
56 |
Correct |
10 ms |
2380 KB |
Output is correct |
57 |
Correct |
9 ms |
2380 KB |
Output is correct |
58 |
Correct |
10 ms |
2380 KB |
Output is correct |
59 |
Correct |
1528 ms |
13152 KB |
Output is correct |
60 |
Correct |
1519 ms |
13344 KB |
Output is correct |
61 |
Correct |
1518 ms |
13184 KB |
Output is correct |
62 |
Correct |
1584 ms |
13284 KB |
Output is correct |
63 |
Correct |
1573 ms |
13232 KB |
Output is correct |
64 |
Correct |
1686 ms |
13196 KB |
Output is correct |
65 |
Correct |
1686 ms |
13240 KB |
Output is correct |
66 |
Correct |
1673 ms |
13216 KB |
Output is correct |
67 |
Correct |
1683 ms |
13208 KB |
Output is correct |
68 |
Correct |
1689 ms |
13208 KB |
Output is correct |
69 |
Correct |
1437 ms |
13260 KB |
Output is correct |
70 |
Correct |
1459 ms |
13176 KB |
Output is correct |
71 |
Correct |
1421 ms |
13436 KB |
Output is correct |
72 |
Correct |
1467 ms |
13148 KB |
Output is correct |
73 |
Correct |
1593 ms |
13092 KB |
Output is correct |
74 |
Correct |
176 ms |
4508 KB |
Output is correct |
75 |
Correct |
174 ms |
4416 KB |
Output is correct |
76 |
Correct |
161 ms |
4504 KB |
Output is correct |
77 |
Correct |
164 ms |
4512 KB |
Output is correct |
78 |
Correct |
176 ms |
4488 KB |
Output is correct |