#include<bits/stdc++.h>
using namespace std;
int mod=1e9+7;
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 ww(int a){
if(a>=mod){
a-=mod;
}
return a;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin>>n;
vector<int>rev(n+6);
for(int i=0;i<=n+5;i++){
rev[i]=mypow(i,mod-2);
}
vector<pair<int,int>>all(n+1);
vector<int>allind;
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;
vector<vector<int>>dp(sz+10,vector<int>(n+5));
vector<int>ps(sz+10);
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]+=1ll*dp[j][h-1]*(cnt-(h-1))%mod*rev[h]%mod;
dp[j][h]=ww(dp[j][h]);
}
dp[j][1]+=1ll*ps[j-1]*cnt%mod;
dp[j][1]=ww(dp[j][1]);
}
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]=ww(ps[i]);
}
}
}
long long res=ps[sz+8];
res+=mod-1;
res%=mod;
cout<<res<<"\n";
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
391 ms |
2260 KB |
Output is correct |
2 |
Correct |
407 ms |
2260 KB |
Output is correct |
3 |
Correct |
403 ms |
2260 KB |
Output is correct |
4 |
Correct |
402 ms |
2380 KB |
Output is correct |
5 |
Correct |
400 ms |
2260 KB |
Output is correct |
6 |
Correct |
416 ms |
2356 KB |
Output is correct |
7 |
Correct |
411 ms |
2356 KB |
Output is correct |
8 |
Correct |
422 ms |
2356 KB |
Output is correct |
9 |
Correct |
407 ms |
2364 KB |
Output is correct |
10 |
Correct |
400 ms |
2368 KB |
Output is correct |
11 |
Correct |
387 ms |
2260 KB |
Output is correct |
12 |
Correct |
414 ms |
2260 KB |
Output is correct |
13 |
Correct |
413 ms |
2260 KB |
Output is correct |
14 |
Correct |
407 ms |
2372 KB |
Output is correct |
15 |
Correct |
412 ms |
2360 KB |
Output is correct |
16 |
Correct |
76 ms |
696 KB |
Output is correct |
17 |
Correct |
84 ms |
724 KB |
Output is correct |
18 |
Correct |
83 ms |
596 KB |
Output is correct |
19 |
Correct |
84 ms |
724 KB |
Output is correct |
20 |
Correct |
82 ms |
712 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
391 ms |
2260 KB |
Output is correct |
2 |
Correct |
407 ms |
2260 KB |
Output is correct |
3 |
Correct |
403 ms |
2260 KB |
Output is correct |
4 |
Correct |
402 ms |
2380 KB |
Output is correct |
5 |
Correct |
400 ms |
2260 KB |
Output is correct |
6 |
Correct |
416 ms |
2356 KB |
Output is correct |
7 |
Correct |
411 ms |
2356 KB |
Output is correct |
8 |
Correct |
422 ms |
2356 KB |
Output is correct |
9 |
Correct |
407 ms |
2364 KB |
Output is correct |
10 |
Correct |
400 ms |
2368 KB |
Output is correct |
11 |
Correct |
387 ms |
2260 KB |
Output is correct |
12 |
Correct |
414 ms |
2260 KB |
Output is correct |
13 |
Correct |
413 ms |
2260 KB |
Output is correct |
14 |
Correct |
407 ms |
2372 KB |
Output is correct |
15 |
Correct |
412 ms |
2360 KB |
Output is correct |
16 |
Correct |
76 ms |
696 KB |
Output is correct |
17 |
Correct |
84 ms |
724 KB |
Output is correct |
18 |
Correct |
83 ms |
596 KB |
Output is correct |
19 |
Correct |
84 ms |
724 KB |
Output is correct |
20 |
Correct |
82 ms |
712 KB |
Output is correct |
21 |
Correct |
1568 ms |
2972 KB |
Output is correct |
22 |
Correct |
1540 ms |
2992 KB |
Output is correct |
23 |
Correct |
1449 ms |
2948 KB |
Output is correct |
24 |
Correct |
1525 ms |
2976 KB |
Output is correct |
25 |
Correct |
1528 ms |
2924 KB |
Output is correct |
26 |
Correct |
1920 ms |
2896 KB |
Output is correct |
27 |
Correct |
1914 ms |
2816 KB |
Output is correct |
28 |
Correct |
1947 ms |
2836 KB |
Output is correct |
29 |
Correct |
1938 ms |
2816 KB |
Output is correct |
30 |
Correct |
600 ms |
3276 KB |
Output is correct |
31 |
Correct |
612 ms |
3276 KB |
Output is correct |
32 |
Correct |
590 ms |
3252 KB |
Output is correct |
33 |
Correct |
584 ms |
3264 KB |
Output is correct |
34 |
Correct |
587 ms |
3260 KB |
Output is correct |
35 |
Correct |
404 ms |
2364 KB |
Output is correct |
36 |
Correct |
410 ms |
2348 KB |
Output is correct |
37 |
Correct |
400 ms |
2348 KB |
Output is correct |
38 |
Correct |
421 ms |
2260 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
460 KB |
Output is correct |
2 |
Correct |
15 ms |
408 KB |
Output is correct |
3 |
Correct |
16 ms |
464 KB |
Output is correct |
4 |
Correct |
18 ms |
460 KB |
Output is correct |
5 |
Correct |
18 ms |
340 KB |
Output is correct |
6 |
Correct |
24 ms |
340 KB |
Output is correct |
7 |
Correct |
23 ms |
340 KB |
Output is correct |
8 |
Correct |
23 ms |
340 KB |
Output is correct |
9 |
Correct |
23 ms |
340 KB |
Output is correct |
10 |
Correct |
24 ms |
456 KB |
Output is correct |
11 |
Correct |
18 ms |
340 KB |
Output is correct |
12 |
Correct |
15 ms |
340 KB |
Output is correct |
13 |
Correct |
17 ms |
464 KB |
Output is correct |
14 |
Correct |
16 ms |
340 KB |
Output is correct |
15 |
Correct |
17 ms |
456 KB |
Output is correct |
16 |
Correct |
8 ms |
340 KB |
Output is correct |
17 |
Correct |
9 ms |
388 KB |
Output is correct |
18 |
Correct |
9 ms |
340 KB |
Output is correct |
19 |
Correct |
8 ms |
340 KB |
Output is correct |
20 |
Correct |
9 ms |
396 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
391 ms |
2260 KB |
Output is correct |
2 |
Correct |
407 ms |
2260 KB |
Output is correct |
3 |
Correct |
403 ms |
2260 KB |
Output is correct |
4 |
Correct |
402 ms |
2380 KB |
Output is correct |
5 |
Correct |
400 ms |
2260 KB |
Output is correct |
6 |
Correct |
416 ms |
2356 KB |
Output is correct |
7 |
Correct |
411 ms |
2356 KB |
Output is correct |
8 |
Correct |
422 ms |
2356 KB |
Output is correct |
9 |
Correct |
407 ms |
2364 KB |
Output is correct |
10 |
Correct |
400 ms |
2368 KB |
Output is correct |
11 |
Correct |
387 ms |
2260 KB |
Output is correct |
12 |
Correct |
414 ms |
2260 KB |
Output is correct |
13 |
Correct |
413 ms |
2260 KB |
Output is correct |
14 |
Correct |
407 ms |
2372 KB |
Output is correct |
15 |
Correct |
412 ms |
2360 KB |
Output is correct |
16 |
Correct |
76 ms |
696 KB |
Output is correct |
17 |
Correct |
84 ms |
724 KB |
Output is correct |
18 |
Correct |
83 ms |
596 KB |
Output is correct |
19 |
Correct |
84 ms |
724 KB |
Output is correct |
20 |
Correct |
82 ms |
712 KB |
Output is correct |
21 |
Correct |
1568 ms |
2972 KB |
Output is correct |
22 |
Correct |
1540 ms |
2992 KB |
Output is correct |
23 |
Correct |
1449 ms |
2948 KB |
Output is correct |
24 |
Correct |
1525 ms |
2976 KB |
Output is correct |
25 |
Correct |
1528 ms |
2924 KB |
Output is correct |
26 |
Correct |
1920 ms |
2896 KB |
Output is correct |
27 |
Correct |
1914 ms |
2816 KB |
Output is correct |
28 |
Correct |
1947 ms |
2836 KB |
Output is correct |
29 |
Correct |
1938 ms |
2816 KB |
Output is correct |
30 |
Correct |
600 ms |
3276 KB |
Output is correct |
31 |
Correct |
612 ms |
3276 KB |
Output is correct |
32 |
Correct |
590 ms |
3252 KB |
Output is correct |
33 |
Correct |
584 ms |
3264 KB |
Output is correct |
34 |
Correct |
587 ms |
3260 KB |
Output is correct |
35 |
Correct |
404 ms |
2364 KB |
Output is correct |
36 |
Correct |
410 ms |
2348 KB |
Output is correct |
37 |
Correct |
400 ms |
2348 KB |
Output is correct |
38 |
Correct |
421 ms |
2260 KB |
Output is correct |
39 |
Correct |
16 ms |
460 KB |
Output is correct |
40 |
Correct |
15 ms |
408 KB |
Output is correct |
41 |
Correct |
16 ms |
464 KB |
Output is correct |
42 |
Correct |
18 ms |
460 KB |
Output is correct |
43 |
Correct |
18 ms |
340 KB |
Output is correct |
44 |
Correct |
24 ms |
340 KB |
Output is correct |
45 |
Correct |
23 ms |
340 KB |
Output is correct |
46 |
Correct |
23 ms |
340 KB |
Output is correct |
47 |
Correct |
23 ms |
340 KB |
Output is correct |
48 |
Correct |
24 ms |
456 KB |
Output is correct |
49 |
Correct |
18 ms |
340 KB |
Output is correct |
50 |
Correct |
15 ms |
340 KB |
Output is correct |
51 |
Correct |
17 ms |
464 KB |
Output is correct |
52 |
Correct |
16 ms |
340 KB |
Output is correct |
53 |
Correct |
17 ms |
456 KB |
Output is correct |
54 |
Correct |
8 ms |
340 KB |
Output is correct |
55 |
Correct |
9 ms |
388 KB |
Output is correct |
56 |
Correct |
9 ms |
340 KB |
Output is correct |
57 |
Correct |
8 ms |
340 KB |
Output is correct |
58 |
Correct |
9 ms |
396 KB |
Output is correct |
59 |
Correct |
1974 ms |
3360 KB |
Output is correct |
60 |
Correct |
1847 ms |
3376 KB |
Output is correct |
61 |
Correct |
1820 ms |
3376 KB |
Output is correct |
62 |
Correct |
1898 ms |
3372 KB |
Output is correct |
63 |
Correct |
1877 ms |
3360 KB |
Output is correct |
64 |
Execution timed out |
2068 ms |
3284 KB |
Time limit exceeded |
65 |
Halted |
0 ms |
0 KB |
- |