#include<bits/stdc++.h>
using namespace std;
int mod=1e9+7;
const int maxn=501;
long long dp[maxn*3+10][maxn+2];
long long ps[maxn*3+10];
int rev[maxn+10];
pair<int,int>all[maxn+10];
vector<int>allind;
long long mypow(long long m,long long y){
if(y==0){
return 1;
}
long long p=mypow(m,(y>>1));
p*=p;
p%=mod;
if(y&1){
p*=m;
p%=mod;
}
return p;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin>>n;
for(int i=0;i<=n+5;i++){
rev[i]=mypow(i,mod-2);
}
for(int i=1;i<=n;i++){
cin>>all[i].first>>all[i].second;
allind.push_back(all[i].first);
allind.push_back(all[i].second);
allind.push_back(all[i].first-1);
}
allind.push_back(0);
sort(allind.begin(),allind.end());
allind.resize(unique(allind.begin(),allind.end())-allind.begin());
int sz=(int)allind.size()+1;
dp[0][0]=1;
for(int i=0;i<sz+10;i++){
ps[i]=1;
}
for(int i=1;i<=n;i++){
int l=lower_bound(allind.begin(),allind.end(),all[i].first)-allind.begin();
int r=lower_bound(allind.begin(),allind.end(),all[i].second)-allind.begin();
for(int j=l;j<=r;j++){
int cnt=allind[j]-allind[j-1];
for(int h=n;h>=2;h--){
dp[j][h]=(dp[j][h]+dp[j][h-1]*(cnt-(h-1))%mod*rev[h])%mod;
}
dp[j][1]=(dp[j][1]+ps[j-1]*cnt)%mod;
}
ps[0]=dp[0][0];
for(int i=1;i<=sz+9;i++){
ps[i]=ps[i-1];
for(int h=0;h<=n;h++){
ps[i]+=dp[i][h];
}
ps[i]%=mod;
}
}
long long res=ps[sz+8];
res+=mod-1;
res%=mod;
cout<<res<<"\n";
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
193 ms |
4172 KB |
Output is correct |
2 |
Correct |
201 ms |
4300 KB |
Output is correct |
3 |
Correct |
217 ms |
4180 KB |
Output is correct |
4 |
Correct |
220 ms |
4236 KB |
Output is correct |
5 |
Correct |
230 ms |
4176 KB |
Output is correct |
6 |
Correct |
210 ms |
4268 KB |
Output is correct |
7 |
Correct |
240 ms |
4184 KB |
Output is correct |
8 |
Correct |
200 ms |
4368 KB |
Output is correct |
9 |
Correct |
259 ms |
4188 KB |
Output is correct |
10 |
Correct |
216 ms |
4176 KB |
Output is correct |
11 |
Correct |
200 ms |
4164 KB |
Output is correct |
12 |
Correct |
192 ms |
4280 KB |
Output is correct |
13 |
Correct |
200 ms |
4256 KB |
Output is correct |
14 |
Correct |
221 ms |
4256 KB |
Output is correct |
15 |
Correct |
233 ms |
4196 KB |
Output is correct |
16 |
Correct |
40 ms |
1008 KB |
Output is correct |
17 |
Correct |
47 ms |
1064 KB |
Output is correct |
18 |
Correct |
39 ms |
980 KB |
Output is correct |
19 |
Correct |
41 ms |
980 KB |
Output is correct |
20 |
Correct |
41 ms |
1036 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
193 ms |
4172 KB |
Output is correct |
2 |
Correct |
201 ms |
4300 KB |
Output is correct |
3 |
Correct |
217 ms |
4180 KB |
Output is correct |
4 |
Correct |
220 ms |
4236 KB |
Output is correct |
5 |
Correct |
230 ms |
4176 KB |
Output is correct |
6 |
Correct |
210 ms |
4268 KB |
Output is correct |
7 |
Correct |
240 ms |
4184 KB |
Output is correct |
8 |
Correct |
200 ms |
4368 KB |
Output is correct |
9 |
Correct |
259 ms |
4188 KB |
Output is correct |
10 |
Correct |
216 ms |
4176 KB |
Output is correct |
11 |
Correct |
200 ms |
4164 KB |
Output is correct |
12 |
Correct |
192 ms |
4280 KB |
Output is correct |
13 |
Correct |
200 ms |
4256 KB |
Output is correct |
14 |
Correct |
221 ms |
4256 KB |
Output is correct |
15 |
Correct |
233 ms |
4196 KB |
Output is correct |
16 |
Correct |
40 ms |
1008 KB |
Output is correct |
17 |
Correct |
47 ms |
1064 KB |
Output is correct |
18 |
Correct |
39 ms |
980 KB |
Output is correct |
19 |
Correct |
41 ms |
980 KB |
Output is correct |
20 |
Correct |
41 ms |
1036 KB |
Output is correct |
21 |
Correct |
1387 ms |
5460 KB |
Output is correct |
22 |
Correct |
1358 ms |
5632 KB |
Output is correct |
23 |
Correct |
1251 ms |
5512 KB |
Output is correct |
24 |
Correct |
1463 ms |
5592 KB |
Output is correct |
25 |
Correct |
1340 ms |
5388 KB |
Output is correct |
26 |
Correct |
1848 ms |
5192 KB |
Output is correct |
27 |
Correct |
1823 ms |
5108 KB |
Output is correct |
28 |
Correct |
1846 ms |
5104 KB |
Output is correct |
29 |
Correct |
1749 ms |
5068 KB |
Output is correct |
30 |
Correct |
315 ms |
6024 KB |
Output is correct |
31 |
Correct |
287 ms |
6092 KB |
Output is correct |
32 |
Correct |
301 ms |
6024 KB |
Output is correct |
33 |
Correct |
278 ms |
6004 KB |
Output is correct |
34 |
Correct |
490 ms |
5924 KB |
Output is correct |
35 |
Correct |
229 ms |
4252 KB |
Output is correct |
36 |
Correct |
195 ms |
4252 KB |
Output is correct |
37 |
Correct |
186 ms |
4204 KB |
Output is correct |
38 |
Correct |
196 ms |
4260 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
15 ms |
1492 KB |
Output is correct |
2 |
Correct |
13 ms |
1484 KB |
Output is correct |
3 |
Correct |
15 ms |
1520 KB |
Output is correct |
4 |
Correct |
15 ms |
1472 KB |
Output is correct |
5 |
Correct |
16 ms |
1516 KB |
Output is correct |
6 |
Correct |
23 ms |
1472 KB |
Output is correct |
7 |
Correct |
21 ms |
1492 KB |
Output is correct |
8 |
Correct |
21 ms |
1492 KB |
Output is correct |
9 |
Correct |
23 ms |
1488 KB |
Output is correct |
10 |
Correct |
21 ms |
1488 KB |
Output is correct |
11 |
Correct |
16 ms |
1516 KB |
Output is correct |
12 |
Correct |
14 ms |
1512 KB |
Output is correct |
13 |
Correct |
16 ms |
1516 KB |
Output is correct |
14 |
Correct |
16 ms |
1492 KB |
Output is correct |
15 |
Correct |
15 ms |
1516 KB |
Output is correct |
16 |
Correct |
8 ms |
796 KB |
Output is correct |
17 |
Correct |
7 ms |
852 KB |
Output is correct |
18 |
Correct |
7 ms |
852 KB |
Output is correct |
19 |
Correct |
7 ms |
852 KB |
Output is correct |
20 |
Correct |
7 ms |
852 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
193 ms |
4172 KB |
Output is correct |
2 |
Correct |
201 ms |
4300 KB |
Output is correct |
3 |
Correct |
217 ms |
4180 KB |
Output is correct |
4 |
Correct |
220 ms |
4236 KB |
Output is correct |
5 |
Correct |
230 ms |
4176 KB |
Output is correct |
6 |
Correct |
210 ms |
4268 KB |
Output is correct |
7 |
Correct |
240 ms |
4184 KB |
Output is correct |
8 |
Correct |
200 ms |
4368 KB |
Output is correct |
9 |
Correct |
259 ms |
4188 KB |
Output is correct |
10 |
Correct |
216 ms |
4176 KB |
Output is correct |
11 |
Correct |
200 ms |
4164 KB |
Output is correct |
12 |
Correct |
192 ms |
4280 KB |
Output is correct |
13 |
Correct |
200 ms |
4256 KB |
Output is correct |
14 |
Correct |
221 ms |
4256 KB |
Output is correct |
15 |
Correct |
233 ms |
4196 KB |
Output is correct |
16 |
Correct |
40 ms |
1008 KB |
Output is correct |
17 |
Correct |
47 ms |
1064 KB |
Output is correct |
18 |
Correct |
39 ms |
980 KB |
Output is correct |
19 |
Correct |
41 ms |
980 KB |
Output is correct |
20 |
Correct |
41 ms |
1036 KB |
Output is correct |
21 |
Correct |
1387 ms |
5460 KB |
Output is correct |
22 |
Correct |
1358 ms |
5632 KB |
Output is correct |
23 |
Correct |
1251 ms |
5512 KB |
Output is correct |
24 |
Correct |
1463 ms |
5592 KB |
Output is correct |
25 |
Correct |
1340 ms |
5388 KB |
Output is correct |
26 |
Correct |
1848 ms |
5192 KB |
Output is correct |
27 |
Correct |
1823 ms |
5108 KB |
Output is correct |
28 |
Correct |
1846 ms |
5104 KB |
Output is correct |
29 |
Correct |
1749 ms |
5068 KB |
Output is correct |
30 |
Correct |
315 ms |
6024 KB |
Output is correct |
31 |
Correct |
287 ms |
6092 KB |
Output is correct |
32 |
Correct |
301 ms |
6024 KB |
Output is correct |
33 |
Correct |
278 ms |
6004 KB |
Output is correct |
34 |
Correct |
490 ms |
5924 KB |
Output is correct |
35 |
Correct |
229 ms |
4252 KB |
Output is correct |
36 |
Correct |
195 ms |
4252 KB |
Output is correct |
37 |
Correct |
186 ms |
4204 KB |
Output is correct |
38 |
Correct |
196 ms |
4260 KB |
Output is correct |
39 |
Correct |
15 ms |
1492 KB |
Output is correct |
40 |
Correct |
13 ms |
1484 KB |
Output is correct |
41 |
Correct |
15 ms |
1520 KB |
Output is correct |
42 |
Correct |
15 ms |
1472 KB |
Output is correct |
43 |
Correct |
16 ms |
1516 KB |
Output is correct |
44 |
Correct |
23 ms |
1472 KB |
Output is correct |
45 |
Correct |
21 ms |
1492 KB |
Output is correct |
46 |
Correct |
21 ms |
1492 KB |
Output is correct |
47 |
Correct |
23 ms |
1488 KB |
Output is correct |
48 |
Correct |
21 ms |
1488 KB |
Output is correct |
49 |
Correct |
16 ms |
1516 KB |
Output is correct |
50 |
Correct |
14 ms |
1512 KB |
Output is correct |
51 |
Correct |
16 ms |
1516 KB |
Output is correct |
52 |
Correct |
16 ms |
1492 KB |
Output is correct |
53 |
Correct |
15 ms |
1516 KB |
Output is correct |
54 |
Correct |
8 ms |
796 KB |
Output is correct |
55 |
Correct |
7 ms |
852 KB |
Output is correct |
56 |
Correct |
7 ms |
852 KB |
Output is correct |
57 |
Correct |
7 ms |
852 KB |
Output is correct |
58 |
Correct |
7 ms |
852 KB |
Output is correct |
59 |
Correct |
1723 ms |
6224 KB |
Output is correct |
60 |
Correct |
1641 ms |
6236 KB |
Output is correct |
61 |
Correct |
1608 ms |
6220 KB |
Output is correct |
62 |
Correct |
1716 ms |
6236 KB |
Output is correct |
63 |
Correct |
1621 ms |
6228 KB |
Output is correct |
64 |
Execution timed out |
2078 ms |
6124 KB |
Time limit exceeded |
65 |
Halted |
0 ms |
0 KB |
- |