#include "bits/stdc++.h"
using namespace std;
#define ar array
//~ #define int long long
const int mod = 1e9 + 7;
int bp(int a, int b){
int r=1;
while(b){
if(b&1) r = r * 1ll * a % mod;
a = a * 1ll * a % mod; b >>= 1;
} return r;
}
signed main(){
ios::sync_with_stdio(0); cin.tie(0);
//~ freopen("in.txt", "r", stdin);
int n; cin>>n;
vector<int> a(2 * n), p(2 * n), og;
iota(p.begin(), p.end(), 0);
for(int i=0;i<n;i++){
cin>>a[i<<1]>>a[i<<1|1];
a[i<<1|1]++;
}
sort(p.begin(), p.end(), [&](int i, int j){
return (a[i] < a[j]);
});
int last=0;
for(int i=0, j=0;i<2*n;last++){
og.push_back(a[p[i]]);
while(j<2*n && a[p[j]] == a[p[i]]) j++;
while(i < j) a[p[i]] = last, i++;
}
vector<int> f(n + 1), inv(n + 1);
f[0] = inv[0] = 1;
for(int i=1;i<=n;i++){
f[i] = f[i-1] * 1ll * i % mod;
inv[i] = bp(f[i], mod - 2);
}
//~ for(int i=0;i<10;i++) cout<<a[i<<1]<<" "<<a[i<<1|1]<<"\n";
auto C = [&](int n, int k){
if(n < k) return 0ll;
return f[n] * 1ll * inv[k] % mod * inv[n - k] % mod;
};
vector<vector<int>> cnt(n + 1, vector<int>(last));
for(int c=1;c<=n;c++){
for(int k=0;k+1<last;k++){
int x = og[k+1] - og[k], f = x;
for(int j=0;j<c && j<x;j++){
cnt[c][k] = (cnt[c][k] + C(c - 1, j) * f % mod * inv[j + 1]) % mod;
f = f * 1ll * (x - j - 1) % mod;
}
}
}
int res = 0;
vector<vector<int>> dp(n, vector<int>(last));
for(int i=0;i<n;i++){
int l = a[i<<1], r = a[i<<1|1];
for(int k=l;k<r;k++){
int c=1;
for(int j=i-1;~j;j--){
if(k){
dp[i][k] = (dp[i][k] + dp[j][k-1] * 1ll * cnt[c][k]) % mod;
}
if(a[j<<1] <= k && k < a[j<<1|1]) c++;
}
dp[i][k] = (dp[i][k] + cnt[c][k]) % mod;
}
for(int k=1;k<last;k++) dp[i][k] = (dp[i][k] + dp[i][k-1]) % mod;
res = (res + dp[i][last - 1]) % mod;
}
cout<<res<<"\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
630 ms |
4236 KB |
Output is correct |
2 |
Correct |
625 ms |
4172 KB |
Output is correct |
3 |
Correct |
667 ms |
4236 KB |
Output is correct |
4 |
Correct |
670 ms |
4240 KB |
Output is correct |
5 |
Correct |
658 ms |
4244 KB |
Output is correct |
6 |
Correct |
697 ms |
4232 KB |
Output is correct |
7 |
Correct |
678 ms |
4244 KB |
Output is correct |
8 |
Correct |
737 ms |
4240 KB |
Output is correct |
9 |
Correct |
748 ms |
4232 KB |
Output is correct |
10 |
Correct |
701 ms |
4252 KB |
Output is correct |
11 |
Correct |
648 ms |
4240 KB |
Output is correct |
12 |
Correct |
635 ms |
4244 KB |
Output is correct |
13 |
Correct |
633 ms |
4232 KB |
Output is correct |
14 |
Correct |
644 ms |
4232 KB |
Output is correct |
15 |
Correct |
637 ms |
4236 KB |
Output is correct |
16 |
Correct |
111 ms |
972 KB |
Output is correct |
17 |
Correct |
117 ms |
1116 KB |
Output is correct |
18 |
Correct |
120 ms |
956 KB |
Output is correct |
19 |
Correct |
122 ms |
988 KB |
Output is correct |
20 |
Correct |
117 ms |
1088 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
630 ms |
4236 KB |
Output is correct |
2 |
Correct |
625 ms |
4172 KB |
Output is correct |
3 |
Correct |
667 ms |
4236 KB |
Output is correct |
4 |
Correct |
670 ms |
4240 KB |
Output is correct |
5 |
Correct |
658 ms |
4244 KB |
Output is correct |
6 |
Correct |
697 ms |
4232 KB |
Output is correct |
7 |
Correct |
678 ms |
4244 KB |
Output is correct |
8 |
Correct |
737 ms |
4240 KB |
Output is correct |
9 |
Correct |
748 ms |
4232 KB |
Output is correct |
10 |
Correct |
701 ms |
4252 KB |
Output is correct |
11 |
Correct |
648 ms |
4240 KB |
Output is correct |
12 |
Correct |
635 ms |
4244 KB |
Output is correct |
13 |
Correct |
633 ms |
4232 KB |
Output is correct |
14 |
Correct |
644 ms |
4232 KB |
Output is correct |
15 |
Correct |
637 ms |
4236 KB |
Output is correct |
16 |
Correct |
111 ms |
972 KB |
Output is correct |
17 |
Correct |
117 ms |
1116 KB |
Output is correct |
18 |
Correct |
120 ms |
956 KB |
Output is correct |
19 |
Correct |
122 ms |
988 KB |
Output is correct |
20 |
Correct |
117 ms |
1088 KB |
Output is correct |
21 |
Correct |
311 ms |
3944 KB |
Output is correct |
22 |
Correct |
314 ms |
4044 KB |
Output is correct |
23 |
Correct |
277 ms |
3916 KB |
Output is correct |
24 |
Correct |
305 ms |
3924 KB |
Output is correct |
25 |
Correct |
311 ms |
3912 KB |
Output is correct |
26 |
Correct |
393 ms |
3752 KB |
Output is correct |
27 |
Correct |
411 ms |
3864 KB |
Output is correct |
28 |
Correct |
410 ms |
3796 KB |
Output is correct |
29 |
Correct |
404 ms |
3800 KB |
Output is correct |
30 |
Correct |
629 ms |
4240 KB |
Output is correct |
31 |
Correct |
631 ms |
4232 KB |
Output is correct |
32 |
Correct |
669 ms |
4228 KB |
Output is correct |
33 |
Correct |
731 ms |
4236 KB |
Output is correct |
34 |
Correct |
677 ms |
4224 KB |
Output is correct |
35 |
Correct |
631 ms |
4224 KB |
Output is correct |
36 |
Correct |
635 ms |
4240 KB |
Output is correct |
37 |
Correct |
630 ms |
4224 KB |
Output is correct |
38 |
Correct |
599 ms |
4228 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
14 ms |
468 KB |
Output is correct |
2 |
Correct |
13 ms |
408 KB |
Output is correct |
3 |
Correct |
14 ms |
408 KB |
Output is correct |
4 |
Correct |
13 ms |
456 KB |
Output is correct |
5 |
Correct |
14 ms |
408 KB |
Output is correct |
6 |
Correct |
15 ms |
468 KB |
Output is correct |
7 |
Correct |
15 ms |
408 KB |
Output is correct |
8 |
Correct |
17 ms |
468 KB |
Output is correct |
9 |
Correct |
14 ms |
404 KB |
Output is correct |
10 |
Correct |
14 ms |
468 KB |
Output is correct |
11 |
Correct |
14 ms |
404 KB |
Output is correct |
12 |
Correct |
12 ms |
400 KB |
Output is correct |
13 |
Correct |
12 ms |
444 KB |
Output is correct |
14 |
Correct |
14 ms |
400 KB |
Output is correct |
15 |
Correct |
16 ms |
408 KB |
Output is correct |
16 |
Correct |
7 ms |
340 KB |
Output is correct |
17 |
Correct |
6 ms |
320 KB |
Output is correct |
18 |
Correct |
6 ms |
340 KB |
Output is correct |
19 |
Correct |
7 ms |
368 KB |
Output is correct |
20 |
Correct |
6 ms |
320 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
630 ms |
4236 KB |
Output is correct |
2 |
Correct |
625 ms |
4172 KB |
Output is correct |
3 |
Correct |
667 ms |
4236 KB |
Output is correct |
4 |
Correct |
670 ms |
4240 KB |
Output is correct |
5 |
Correct |
658 ms |
4244 KB |
Output is correct |
6 |
Correct |
697 ms |
4232 KB |
Output is correct |
7 |
Correct |
678 ms |
4244 KB |
Output is correct |
8 |
Correct |
737 ms |
4240 KB |
Output is correct |
9 |
Correct |
748 ms |
4232 KB |
Output is correct |
10 |
Correct |
701 ms |
4252 KB |
Output is correct |
11 |
Correct |
648 ms |
4240 KB |
Output is correct |
12 |
Correct |
635 ms |
4244 KB |
Output is correct |
13 |
Correct |
633 ms |
4232 KB |
Output is correct |
14 |
Correct |
644 ms |
4232 KB |
Output is correct |
15 |
Correct |
637 ms |
4236 KB |
Output is correct |
16 |
Correct |
111 ms |
972 KB |
Output is correct |
17 |
Correct |
117 ms |
1116 KB |
Output is correct |
18 |
Correct |
120 ms |
956 KB |
Output is correct |
19 |
Correct |
122 ms |
988 KB |
Output is correct |
20 |
Correct |
117 ms |
1088 KB |
Output is correct |
21 |
Correct |
311 ms |
3944 KB |
Output is correct |
22 |
Correct |
314 ms |
4044 KB |
Output is correct |
23 |
Correct |
277 ms |
3916 KB |
Output is correct |
24 |
Correct |
305 ms |
3924 KB |
Output is correct |
25 |
Correct |
311 ms |
3912 KB |
Output is correct |
26 |
Correct |
393 ms |
3752 KB |
Output is correct |
27 |
Correct |
411 ms |
3864 KB |
Output is correct |
28 |
Correct |
410 ms |
3796 KB |
Output is correct |
29 |
Correct |
404 ms |
3800 KB |
Output is correct |
30 |
Correct |
629 ms |
4240 KB |
Output is correct |
31 |
Correct |
631 ms |
4232 KB |
Output is correct |
32 |
Correct |
669 ms |
4228 KB |
Output is correct |
33 |
Correct |
731 ms |
4236 KB |
Output is correct |
34 |
Correct |
677 ms |
4224 KB |
Output is correct |
35 |
Correct |
631 ms |
4224 KB |
Output is correct |
36 |
Correct |
635 ms |
4240 KB |
Output is correct |
37 |
Correct |
630 ms |
4224 KB |
Output is correct |
38 |
Correct |
599 ms |
4228 KB |
Output is correct |
39 |
Correct |
14 ms |
468 KB |
Output is correct |
40 |
Correct |
13 ms |
408 KB |
Output is correct |
41 |
Correct |
14 ms |
408 KB |
Output is correct |
42 |
Correct |
13 ms |
456 KB |
Output is correct |
43 |
Correct |
14 ms |
408 KB |
Output is correct |
44 |
Correct |
15 ms |
468 KB |
Output is correct |
45 |
Correct |
15 ms |
408 KB |
Output is correct |
46 |
Correct |
17 ms |
468 KB |
Output is correct |
47 |
Correct |
14 ms |
404 KB |
Output is correct |
48 |
Correct |
14 ms |
468 KB |
Output is correct |
49 |
Correct |
14 ms |
404 KB |
Output is correct |
50 |
Correct |
12 ms |
400 KB |
Output is correct |
51 |
Correct |
12 ms |
444 KB |
Output is correct |
52 |
Correct |
14 ms |
400 KB |
Output is correct |
53 |
Correct |
16 ms |
408 KB |
Output is correct |
54 |
Correct |
7 ms |
340 KB |
Output is correct |
55 |
Correct |
6 ms |
320 KB |
Output is correct |
56 |
Correct |
6 ms |
340 KB |
Output is correct |
57 |
Correct |
7 ms |
368 KB |
Output is correct |
58 |
Correct |
6 ms |
320 KB |
Output is correct |
59 |
Correct |
1571 ms |
4292 KB |
Output is correct |
60 |
Correct |
1544 ms |
4304 KB |
Output is correct |
61 |
Correct |
1502 ms |
4300 KB |
Output is correct |
62 |
Correct |
1512 ms |
4232 KB |
Output is correct |
63 |
Correct |
1501 ms |
4240 KB |
Output is correct |
64 |
Correct |
1658 ms |
4248 KB |
Output is correct |
65 |
Correct |
1649 ms |
4292 KB |
Output is correct |
66 |
Correct |
1636 ms |
4244 KB |
Output is correct |
67 |
Correct |
1662 ms |
4292 KB |
Output is correct |
68 |
Correct |
1650 ms |
4236 KB |
Output is correct |
69 |
Correct |
1467 ms |
4236 KB |
Output is correct |
70 |
Correct |
1495 ms |
4236 KB |
Output is correct |
71 |
Correct |
1504 ms |
4236 KB |
Output is correct |
72 |
Correct |
1473 ms |
4236 KB |
Output is correct |
73 |
Correct |
1516 ms |
4236 KB |
Output is correct |
74 |
Correct |
182 ms |
956 KB |
Output is correct |
75 |
Correct |
184 ms |
1088 KB |
Output is correct |
76 |
Correct |
183 ms |
980 KB |
Output is correct |
77 |
Correct |
179 ms |
964 KB |
Output is correct |
78 |
Correct |
182 ms |
972 KB |
Output is correct |