#include <bits/stdc++.h>
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2")
//#pragma GCC optimize("unroll-loops")
#define rep(i,l,r) for (int i = l; i < r; i++)
#define repr(i,r,l) for (int i = r; i >= l; i--)
#define X first
#define Y second
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define endl '\n'
#define debug(x) cerr << #x << " : " << x << endl;
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pll;
constexpr int N = 5e2+20,mod = 1e9+7 ,inf = 1e9+10,maxm = (1 << 10)+10;
inline int mkay(int a,int b){
if (a+b >= mod) return a+b-mod;
if (a+b < 0) return a+b+mod;
return a+b;
}
inline int poww(int a,int k){
if (k < 0) return 0;
int z = 1;
while (k){
if (k&1) z = 1ll*z*a%mod;
a = 1ll*a*a%mod;
k >>= 1;
}
return z;
}
int dp[2][2*N][N],sum[2][2*N];
int a[N],b[N],n,inv[N*2];
int main(){
vector<int> ve;
cin >> n;
ve.reserve(2*n);
rep(i,1,n+1){
cin >> a[i] >> b[i];
b[i]++;
ve.pb(a[i]);
ve.pb(b[i]);
}
sort(all(ve));
rep(i,1,n+1){
a[i] = lower_bound(all(ve),a[i])-ve.begin();
b[i] = lower_bound(all(ve),b[i])-ve.begin();
}
int nn = 2*n+1;
rep(i,0,n+2) inv[i] = poww(i,mod-2);
rep(i,1,n+1){
bool f = (i&1);
rep(j,0,nn){
sum[f][j] = 0;
rep(k,1,n+1){
if (k > i) break;
dp[f][j][k] = dp[1-f][j][k];
if (j < a[i] || j >= b[i]){
sum[f][j] = (sum[f][j]+dp[f][j][k])%mod;
continue;
}
if (k > 1){
dp[f][j][k] = (dp[f][j][k]+1ll*dp[1-f][j][k-1]*inv[k]%mod*(ve[j+1]-ve[j]-k+1)%mod)%mod;
}
else{
dp[f][j][k] = (dp[f][j][k]+ve[j+1]-ve[j])%mod;
rep(g,0,j){
dp[f][j][k] = (dp[f][j][k]+1ll*(ve[j+1]-ve[j])*sum[1-f][g]%mod)%mod;
}
}
sum[f][j] = (sum[f][j]+dp[f][j][k])%mod;
}
}
}
bool f = n%2;
int ans = 0;
rep(i,0,nn){
ans = (ans+sum[f][i])%mod;
}
cout << ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
733 ms |
4392 KB |
Output is correct |
2 |
Correct |
754 ms |
4392 KB |
Output is correct |
3 |
Correct |
746 ms |
4392 KB |
Output is correct |
4 |
Correct |
760 ms |
4392 KB |
Output is correct |
5 |
Correct |
785 ms |
4388 KB |
Output is correct |
6 |
Correct |
798 ms |
4308 KB |
Output is correct |
7 |
Correct |
806 ms |
4392 KB |
Output is correct |
8 |
Correct |
805 ms |
4308 KB |
Output is correct |
9 |
Correct |
817 ms |
4396 KB |
Output is correct |
10 |
Correct |
856 ms |
4392 KB |
Output is correct |
11 |
Correct |
785 ms |
4392 KB |
Output is correct |
12 |
Correct |
812 ms |
4388 KB |
Output is correct |
13 |
Correct |
833 ms |
4392 KB |
Output is correct |
14 |
Correct |
827 ms |
4388 KB |
Output is correct |
15 |
Correct |
792 ms |
4392 KB |
Output is correct |
16 |
Correct |
875 ms |
4392 KB |
Output is correct |
17 |
Correct |
1053 ms |
4388 KB |
Output is correct |
18 |
Correct |
835 ms |
4388 KB |
Output is correct |
19 |
Correct |
842 ms |
4388 KB |
Output is correct |
20 |
Correct |
843 ms |
4388 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
733 ms |
4392 KB |
Output is correct |
2 |
Correct |
754 ms |
4392 KB |
Output is correct |
3 |
Correct |
746 ms |
4392 KB |
Output is correct |
4 |
Correct |
760 ms |
4392 KB |
Output is correct |
5 |
Correct |
785 ms |
4388 KB |
Output is correct |
6 |
Correct |
798 ms |
4308 KB |
Output is correct |
7 |
Correct |
806 ms |
4392 KB |
Output is correct |
8 |
Correct |
805 ms |
4308 KB |
Output is correct |
9 |
Correct |
817 ms |
4396 KB |
Output is correct |
10 |
Correct |
856 ms |
4392 KB |
Output is correct |
11 |
Correct |
785 ms |
4392 KB |
Output is correct |
12 |
Correct |
812 ms |
4388 KB |
Output is correct |
13 |
Correct |
833 ms |
4392 KB |
Output is correct |
14 |
Correct |
827 ms |
4388 KB |
Output is correct |
15 |
Correct |
792 ms |
4392 KB |
Output is correct |
16 |
Correct |
875 ms |
4392 KB |
Output is correct |
17 |
Correct |
1053 ms |
4388 KB |
Output is correct |
18 |
Correct |
835 ms |
4388 KB |
Output is correct |
19 |
Correct |
842 ms |
4388 KB |
Output is correct |
20 |
Correct |
843 ms |
4388 KB |
Output is correct |
21 |
Correct |
1502 ms |
4400 KB |
Output is correct |
22 |
Correct |
1338 ms |
4388 KB |
Output is correct |
23 |
Correct |
1327 ms |
4388 KB |
Output is correct |
24 |
Correct |
1405 ms |
4388 KB |
Output is correct |
25 |
Correct |
1370 ms |
4392 KB |
Output is correct |
26 |
Correct |
1723 ms |
4392 KB |
Output is correct |
27 |
Correct |
1672 ms |
4388 KB |
Output is correct |
28 |
Correct |
1654 ms |
4384 KB |
Output is correct |
29 |
Correct |
1688 ms |
4384 KB |
Output is correct |
30 |
Correct |
874 ms |
4388 KB |
Output is correct |
31 |
Correct |
799 ms |
4388 KB |
Output is correct |
32 |
Correct |
757 ms |
4388 KB |
Output is correct |
33 |
Correct |
775 ms |
4392 KB |
Output is correct |
34 |
Correct |
820 ms |
4388 KB |
Output is correct |
35 |
Correct |
832 ms |
4388 KB |
Output is correct |
36 |
Correct |
756 ms |
4392 KB |
Output is correct |
37 |
Correct |
795 ms |
4396 KB |
Output is correct |
38 |
Correct |
799 ms |
4396 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
11 ms |
1108 KB |
Output is correct |
2 |
Correct |
10 ms |
1080 KB |
Output is correct |
3 |
Correct |
11 ms |
1108 KB |
Output is correct |
4 |
Correct |
12 ms |
1108 KB |
Output is correct |
5 |
Correct |
15 ms |
1108 KB |
Output is correct |
6 |
Correct |
13 ms |
1156 KB |
Output is correct |
7 |
Correct |
14 ms |
1148 KB |
Output is correct |
8 |
Correct |
14 ms |
1152 KB |
Output is correct |
9 |
Correct |
13 ms |
1152 KB |
Output is correct |
10 |
Correct |
13 ms |
1108 KB |
Output is correct |
11 |
Correct |
11 ms |
1108 KB |
Output is correct |
12 |
Correct |
12 ms |
1148 KB |
Output is correct |
13 |
Correct |
11 ms |
1108 KB |
Output is correct |
14 |
Correct |
10 ms |
1108 KB |
Output is correct |
15 |
Correct |
12 ms |
1108 KB |
Output is correct |
16 |
Correct |
12 ms |
1152 KB |
Output is correct |
17 |
Correct |
11 ms |
1108 KB |
Output is correct |
18 |
Correct |
11 ms |
1152 KB |
Output is correct |
19 |
Correct |
11 ms |
1108 KB |
Output is correct |
20 |
Correct |
13 ms |
1084 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
733 ms |
4392 KB |
Output is correct |
2 |
Correct |
754 ms |
4392 KB |
Output is correct |
3 |
Correct |
746 ms |
4392 KB |
Output is correct |
4 |
Correct |
760 ms |
4392 KB |
Output is correct |
5 |
Correct |
785 ms |
4388 KB |
Output is correct |
6 |
Correct |
798 ms |
4308 KB |
Output is correct |
7 |
Correct |
806 ms |
4392 KB |
Output is correct |
8 |
Correct |
805 ms |
4308 KB |
Output is correct |
9 |
Correct |
817 ms |
4396 KB |
Output is correct |
10 |
Correct |
856 ms |
4392 KB |
Output is correct |
11 |
Correct |
785 ms |
4392 KB |
Output is correct |
12 |
Correct |
812 ms |
4388 KB |
Output is correct |
13 |
Correct |
833 ms |
4392 KB |
Output is correct |
14 |
Correct |
827 ms |
4388 KB |
Output is correct |
15 |
Correct |
792 ms |
4392 KB |
Output is correct |
16 |
Correct |
875 ms |
4392 KB |
Output is correct |
17 |
Correct |
1053 ms |
4388 KB |
Output is correct |
18 |
Correct |
835 ms |
4388 KB |
Output is correct |
19 |
Correct |
842 ms |
4388 KB |
Output is correct |
20 |
Correct |
843 ms |
4388 KB |
Output is correct |
21 |
Correct |
1502 ms |
4400 KB |
Output is correct |
22 |
Correct |
1338 ms |
4388 KB |
Output is correct |
23 |
Correct |
1327 ms |
4388 KB |
Output is correct |
24 |
Correct |
1405 ms |
4388 KB |
Output is correct |
25 |
Correct |
1370 ms |
4392 KB |
Output is correct |
26 |
Correct |
1723 ms |
4392 KB |
Output is correct |
27 |
Correct |
1672 ms |
4388 KB |
Output is correct |
28 |
Correct |
1654 ms |
4384 KB |
Output is correct |
29 |
Correct |
1688 ms |
4384 KB |
Output is correct |
30 |
Correct |
874 ms |
4388 KB |
Output is correct |
31 |
Correct |
799 ms |
4388 KB |
Output is correct |
32 |
Correct |
757 ms |
4388 KB |
Output is correct |
33 |
Correct |
775 ms |
4392 KB |
Output is correct |
34 |
Correct |
820 ms |
4388 KB |
Output is correct |
35 |
Correct |
832 ms |
4388 KB |
Output is correct |
36 |
Correct |
756 ms |
4392 KB |
Output is correct |
37 |
Correct |
795 ms |
4396 KB |
Output is correct |
38 |
Correct |
799 ms |
4396 KB |
Output is correct |
39 |
Correct |
11 ms |
1108 KB |
Output is correct |
40 |
Correct |
10 ms |
1080 KB |
Output is correct |
41 |
Correct |
11 ms |
1108 KB |
Output is correct |
42 |
Correct |
12 ms |
1108 KB |
Output is correct |
43 |
Correct |
15 ms |
1108 KB |
Output is correct |
44 |
Correct |
13 ms |
1156 KB |
Output is correct |
45 |
Correct |
14 ms |
1148 KB |
Output is correct |
46 |
Correct |
14 ms |
1152 KB |
Output is correct |
47 |
Correct |
13 ms |
1152 KB |
Output is correct |
48 |
Correct |
13 ms |
1108 KB |
Output is correct |
49 |
Correct |
11 ms |
1108 KB |
Output is correct |
50 |
Correct |
12 ms |
1148 KB |
Output is correct |
51 |
Correct |
11 ms |
1108 KB |
Output is correct |
52 |
Correct |
10 ms |
1108 KB |
Output is correct |
53 |
Correct |
12 ms |
1108 KB |
Output is correct |
54 |
Correct |
12 ms |
1152 KB |
Output is correct |
55 |
Correct |
11 ms |
1108 KB |
Output is correct |
56 |
Correct |
11 ms |
1152 KB |
Output is correct |
57 |
Correct |
11 ms |
1108 KB |
Output is correct |
58 |
Correct |
13 ms |
1084 KB |
Output is correct |
59 |
Correct |
1292 ms |
4392 KB |
Output is correct |
60 |
Correct |
1234 ms |
4392 KB |
Output is correct |
61 |
Correct |
1204 ms |
4388 KB |
Output is correct |
62 |
Correct |
1265 ms |
4392 KB |
Output is correct |
63 |
Correct |
1231 ms |
4392 KB |
Output is correct |
64 |
Correct |
1476 ms |
4396 KB |
Output is correct |
65 |
Correct |
1479 ms |
4396 KB |
Output is correct |
66 |
Correct |
1492 ms |
4396 KB |
Output is correct |
67 |
Correct |
1461 ms |
4392 KB |
Output is correct |
68 |
Correct |
1489 ms |
4392 KB |
Output is correct |
69 |
Correct |
1183 ms |
4400 KB |
Output is correct |
70 |
Correct |
1170 ms |
4396 KB |
Output is correct |
71 |
Correct |
1186 ms |
4392 KB |
Output is correct |
72 |
Correct |
1197 ms |
4392 KB |
Output is correct |
73 |
Correct |
1208 ms |
4388 KB |
Output is correct |
74 |
Correct |
1236 ms |
4392 KB |
Output is correct |
75 |
Correct |
1253 ms |
4392 KB |
Output is correct |
76 |
Correct |
1249 ms |
4392 KB |
Output is correct |
77 |
Correct |
1255 ms |
4392 KB |
Output is correct |
78 |
Correct |
1364 ms |
4392 KB |
Output is correct |