/*
Code written by Talant I.D.
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
const int mod = 1e9+7;
ll mode(ll a) {
a %= mod;
if (a < 0) a += mod;
return a;
}
ll subt(ll a, ll b) {
return mode(mode(a)-mode(b));
}
ll add(ll a, ll b) {
return mode(mode(a)+mode(b));
}
ll mult(ll a, ll b) {
return mode(mode(a)*mode(b));
}
ll binpow(ll a, ll b) {
ll res = 1;
while (b) {
if (b&1) res = mult(res, a);
a = mult(a, a);
b >>= 1;
}
return res;
}
ll divide(ll a, ll b) {
return mult(a, binpow(b, mod-2));
}
const int N = 1010;
int a[N], b[N], rng[N];
ll dp[N][N];
ll inv[N];
int n;
int main() {
do_not_disturb
vector <int> compressed;
inv[1] = 1;
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
b[i]++;
compressed.pb(a[i]);
compressed.pb(b[i]);
if (i > 1) inv[i] = binpow(i, mod-2);
}
sort(all(compressed));
compressed.resize(unique(all(compressed))-compressed.begin());
auto m = sz(compressed);
for (int j = 0; j < m-1; j++) {
rng[j+1] = compressed[j+1]-compressed[j];
}
for (int i = 1; i <= n; i++) {
a[i] = lb(all(compressed), a[i])-compressed.begin()+1;
b[i] = lb(all(compressed), b[i])-compressed.begin()+1;
}
for (int j = 0; j < m; j++) {
dp[0][j] = 1;
}
ll ans = 0;
for (int i = 1; i <= n; i++) {
for (int j = a[i]; j < b[i]; j++) {
ll res = rng[j];
ll x = rng[j], y = 1;
for (int k = i-1; k >= 0; k--) {
dp[i][j] = add(dp[i][j], res*dp[k][j-1]);
if (a[k] <= j && j < b[k]) {
x++; y++;
res = mult(mult(res, x), inv[y]);
}
}
}
for (int j = 1; j < m; j++) {
dp[i][j] = add(dp[i][j], dp[i][j-1]);
}
ans = add(ans, dp[i][m-1]);
}
cout << ans;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
4220 KB |
Output is correct |
2 |
Correct |
11 ms |
4300 KB |
Output is correct |
3 |
Correct |
11 ms |
4300 KB |
Output is correct |
4 |
Correct |
11 ms |
4284 KB |
Output is correct |
5 |
Correct |
11 ms |
4300 KB |
Output is correct |
6 |
Correct |
11 ms |
4300 KB |
Output is correct |
7 |
Correct |
11 ms |
4232 KB |
Output is correct |
8 |
Correct |
10 ms |
4260 KB |
Output is correct |
9 |
Correct |
11 ms |
4308 KB |
Output is correct |
10 |
Correct |
11 ms |
4228 KB |
Output is correct |
11 |
Correct |
11 ms |
4300 KB |
Output is correct |
12 |
Correct |
11 ms |
4308 KB |
Output is correct |
13 |
Correct |
10 ms |
4300 KB |
Output is correct |
14 |
Correct |
11 ms |
4300 KB |
Output is correct |
15 |
Correct |
10 ms |
4300 KB |
Output is correct |
16 |
Correct |
5 ms |
3020 KB |
Output is correct |
17 |
Correct |
5 ms |
3020 KB |
Output is correct |
18 |
Correct |
5 ms |
3020 KB |
Output is correct |
19 |
Correct |
5 ms |
3020 KB |
Output is correct |
20 |
Correct |
5 ms |
3020 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
4220 KB |
Output is correct |
2 |
Correct |
11 ms |
4300 KB |
Output is correct |
3 |
Correct |
11 ms |
4300 KB |
Output is correct |
4 |
Correct |
11 ms |
4284 KB |
Output is correct |
5 |
Correct |
11 ms |
4300 KB |
Output is correct |
6 |
Correct |
11 ms |
4300 KB |
Output is correct |
7 |
Correct |
11 ms |
4232 KB |
Output is correct |
8 |
Correct |
10 ms |
4260 KB |
Output is correct |
9 |
Correct |
11 ms |
4308 KB |
Output is correct |
10 |
Correct |
11 ms |
4228 KB |
Output is correct |
11 |
Correct |
11 ms |
4300 KB |
Output is correct |
12 |
Correct |
11 ms |
4308 KB |
Output is correct |
13 |
Correct |
10 ms |
4300 KB |
Output is correct |
14 |
Correct |
11 ms |
4300 KB |
Output is correct |
15 |
Correct |
10 ms |
4300 KB |
Output is correct |
16 |
Correct |
5 ms |
3020 KB |
Output is correct |
17 |
Correct |
5 ms |
3020 KB |
Output is correct |
18 |
Correct |
5 ms |
3020 KB |
Output is correct |
19 |
Correct |
5 ms |
3020 KB |
Output is correct |
20 |
Correct |
5 ms |
3020 KB |
Output is correct |
21 |
Correct |
502 ms |
4320 KB |
Output is correct |
22 |
Correct |
478 ms |
4272 KB |
Output is correct |
23 |
Correct |
445 ms |
4308 KB |
Output is correct |
24 |
Correct |
478 ms |
4304 KB |
Output is correct |
25 |
Correct |
473 ms |
4292 KB |
Output is correct |
26 |
Correct |
798 ms |
4420 KB |
Output is correct |
27 |
Correct |
825 ms |
4292 KB |
Output is correct |
28 |
Correct |
812 ms |
4412 KB |
Output is correct |
29 |
Correct |
783 ms |
4356 KB |
Output is correct |
30 |
Correct |
13 ms |
4200 KB |
Output is correct |
31 |
Correct |
14 ms |
4220 KB |
Output is correct |
32 |
Correct |
13 ms |
4304 KB |
Output is correct |
33 |
Correct |
13 ms |
4212 KB |
Output is correct |
34 |
Correct |
13 ms |
4304 KB |
Output is correct |
35 |
Correct |
13 ms |
4264 KB |
Output is correct |
36 |
Correct |
13 ms |
4300 KB |
Output is correct |
37 |
Correct |
13 ms |
4236 KB |
Output is correct |
38 |
Correct |
13 ms |
4300 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
824 KB |
Output is correct |
2 |
Correct |
5 ms |
844 KB |
Output is correct |
3 |
Correct |
5 ms |
844 KB |
Output is correct |
4 |
Correct |
5 ms |
844 KB |
Output is correct |
5 |
Correct |
6 ms |
892 KB |
Output is correct |
6 |
Correct |
8 ms |
864 KB |
Output is correct |
7 |
Correct |
8 ms |
844 KB |
Output is correct |
8 |
Correct |
8 ms |
844 KB |
Output is correct |
9 |
Correct |
8 ms |
832 KB |
Output is correct |
10 |
Correct |
8 ms |
800 KB |
Output is correct |
11 |
Correct |
5 ms |
848 KB |
Output is correct |
12 |
Correct |
4 ms |
844 KB |
Output is correct |
13 |
Correct |
5 ms |
844 KB |
Output is correct |
14 |
Correct |
5 ms |
844 KB |
Output is correct |
15 |
Correct |
5 ms |
844 KB |
Output is correct |
16 |
Correct |
4 ms |
764 KB |
Output is correct |
17 |
Correct |
4 ms |
844 KB |
Output is correct |
18 |
Correct |
4 ms |
844 KB |
Output is correct |
19 |
Correct |
4 ms |
844 KB |
Output is correct |
20 |
Correct |
4 ms |
844 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
4220 KB |
Output is correct |
2 |
Correct |
11 ms |
4300 KB |
Output is correct |
3 |
Correct |
11 ms |
4300 KB |
Output is correct |
4 |
Correct |
11 ms |
4284 KB |
Output is correct |
5 |
Correct |
11 ms |
4300 KB |
Output is correct |
6 |
Correct |
11 ms |
4300 KB |
Output is correct |
7 |
Correct |
11 ms |
4232 KB |
Output is correct |
8 |
Correct |
10 ms |
4260 KB |
Output is correct |
9 |
Correct |
11 ms |
4308 KB |
Output is correct |
10 |
Correct |
11 ms |
4228 KB |
Output is correct |
11 |
Correct |
11 ms |
4300 KB |
Output is correct |
12 |
Correct |
11 ms |
4308 KB |
Output is correct |
13 |
Correct |
10 ms |
4300 KB |
Output is correct |
14 |
Correct |
11 ms |
4300 KB |
Output is correct |
15 |
Correct |
10 ms |
4300 KB |
Output is correct |
16 |
Correct |
5 ms |
3020 KB |
Output is correct |
17 |
Correct |
5 ms |
3020 KB |
Output is correct |
18 |
Correct |
5 ms |
3020 KB |
Output is correct |
19 |
Correct |
5 ms |
3020 KB |
Output is correct |
20 |
Correct |
5 ms |
3020 KB |
Output is correct |
21 |
Correct |
502 ms |
4320 KB |
Output is correct |
22 |
Correct |
478 ms |
4272 KB |
Output is correct |
23 |
Correct |
445 ms |
4308 KB |
Output is correct |
24 |
Correct |
478 ms |
4304 KB |
Output is correct |
25 |
Correct |
473 ms |
4292 KB |
Output is correct |
26 |
Correct |
798 ms |
4420 KB |
Output is correct |
27 |
Correct |
825 ms |
4292 KB |
Output is correct |
28 |
Correct |
812 ms |
4412 KB |
Output is correct |
29 |
Correct |
783 ms |
4356 KB |
Output is correct |
30 |
Correct |
13 ms |
4200 KB |
Output is correct |
31 |
Correct |
14 ms |
4220 KB |
Output is correct |
32 |
Correct |
13 ms |
4304 KB |
Output is correct |
33 |
Correct |
13 ms |
4212 KB |
Output is correct |
34 |
Correct |
13 ms |
4304 KB |
Output is correct |
35 |
Correct |
13 ms |
4264 KB |
Output is correct |
36 |
Correct |
13 ms |
4300 KB |
Output is correct |
37 |
Correct |
13 ms |
4236 KB |
Output is correct |
38 |
Correct |
13 ms |
4300 KB |
Output is correct |
39 |
Correct |
5 ms |
824 KB |
Output is correct |
40 |
Correct |
5 ms |
844 KB |
Output is correct |
41 |
Correct |
5 ms |
844 KB |
Output is correct |
42 |
Correct |
5 ms |
844 KB |
Output is correct |
43 |
Correct |
6 ms |
892 KB |
Output is correct |
44 |
Correct |
8 ms |
864 KB |
Output is correct |
45 |
Correct |
8 ms |
844 KB |
Output is correct |
46 |
Correct |
8 ms |
844 KB |
Output is correct |
47 |
Correct |
8 ms |
832 KB |
Output is correct |
48 |
Correct |
8 ms |
800 KB |
Output is correct |
49 |
Correct |
5 ms |
848 KB |
Output is correct |
50 |
Correct |
4 ms |
844 KB |
Output is correct |
51 |
Correct |
5 ms |
844 KB |
Output is correct |
52 |
Correct |
5 ms |
844 KB |
Output is correct |
53 |
Correct |
5 ms |
844 KB |
Output is correct |
54 |
Correct |
4 ms |
764 KB |
Output is correct |
55 |
Correct |
4 ms |
844 KB |
Output is correct |
56 |
Correct |
4 ms |
844 KB |
Output is correct |
57 |
Correct |
4 ms |
844 KB |
Output is correct |
58 |
Correct |
4 ms |
844 KB |
Output is correct |
59 |
Correct |
537 ms |
4312 KB |
Output is correct |
60 |
Correct |
505 ms |
4292 KB |
Output is correct |
61 |
Correct |
481 ms |
4304 KB |
Output is correct |
62 |
Correct |
535 ms |
4300 KB |
Output is correct |
63 |
Correct |
530 ms |
4352 KB |
Output is correct |
64 |
Correct |
912 ms |
4324 KB |
Output is correct |
65 |
Correct |
918 ms |
4380 KB |
Output is correct |
66 |
Correct |
911 ms |
4380 KB |
Output is correct |
67 |
Correct |
909 ms |
4224 KB |
Output is correct |
68 |
Correct |
922 ms |
4240 KB |
Output is correct |
69 |
Correct |
423 ms |
4296 KB |
Output is correct |
70 |
Correct |
417 ms |
4284 KB |
Output is correct |
71 |
Correct |
422 ms |
4320 KB |
Output is correct |
72 |
Correct |
434 ms |
4292 KB |
Output is correct |
73 |
Correct |
445 ms |
4428 KB |
Output is correct |
74 |
Correct |
108 ms |
3012 KB |
Output is correct |
75 |
Correct |
103 ms |
3044 KB |
Output is correct |
76 |
Correct |
107 ms |
3036 KB |
Output is correct |
77 |
Correct |
107 ms |
3016 KB |
Output is correct |
78 |
Correct |
121 ms |
3048 KB |
Output is correct |