#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
using namespace std;
int const mod=1e9+7;
map<int,int> ind;
vector<int> val;
vector<int> fen(1010,0);
void upd(int idx,int val)
{
idx+=2;
for(int i=idx;i<1010;i+=i&-i)fen[i]+=val,fen[i]%=mod;
}
int qr(int idx)
{
idx+=2;
int ret=0;
for(int i=idx;i>0;i-=i&-i)ret+=fen[i],ret%=mod;
return ret;
}
int pow(int a,int b)
{
if(b==0)return 1;
if(b==1)return a;
int ret=pow(a,b/2);
if(b%2==0)return (ret*ret)%mod;
else return (((ret*ret)%mod)*a)%mod;
}
vector<int> inverse(510);
void inv(int a)
{
inverse[a]=pow(a,mod-2);
}
int choose(int a,int b)
{
if(b>a)return 0;
if(a==b)return 1;
if(a-b<b)b=a-b;
int ret=1;
for(int i=b+1;i<=a;i++)
{
ret*=i;
ret%=mod;
}
for(int i=2;i<=a-b;i++)
{
ret*=inverse[i];
ret%=mod;
}
return ret;
}
signed main()
{
for(int i=2;i<510;i++)inv(i);
int n;
cin>>n;
vector<pii> info;
set<int> temp;
for(int i=0;i<n;i++)
{
int a,b;
cin>>a>>b;
temp.insert(a);
temp.insert(b+1);
info.push_back({a,b+1});
}
for(auto it:temp)
{
val.push_back(it);
ind[it]=val.size()-1;
}
vector<vector<int>> pre(510,vector<int>(1010,-2));
vector<int> latest(1010,-1);
upd(-1,1);
vector<vector<int>> dp(510,vector<int>(1010,0));
for(int i=0;i<n;i++)
{
//cout<<endl<<i<<":";
for(int j=ind[info[i].se]-1;j>=ind[info[i].fi];j--)
{
//cout<<j<<" ";
int bef=latest[j];
pre[i][j]=latest[j];
latest[j]=i;
int a=qr(j),b=(val[j+1]-val[j]),c=0;
dp[i][j]=a;
int ans=a*b;
ans%=mod;
int k=2;
//cout<<i<<" "<<j<<" "<<ans<<" ";
while(bef!=-1)
{
ans+=dp[bef][j]*choose(b+k-2,k);
ans%=mod;
bef=pre[bef][j];
k++;
//cout<<endl<<bef<<" "<<ans<<" ";
}
// cout<<endl;
upd(j+1,ans);
}
}
cout<<(qr(1007)+mod-1)%mod;
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:91:45: warning: unused variable 'c' [-Wunused-variable]
91 | int a=qr(j),b=(val[j+1]-val[j]),c=0;
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
8536 KB |
Output is correct |
2 |
Correct |
4 ms |
8536 KB |
Output is correct |
3 |
Correct |
4 ms |
8540 KB |
Output is correct |
4 |
Correct |
4 ms |
8540 KB |
Output is correct |
5 |
Correct |
4 ms |
8540 KB |
Output is correct |
6 |
Correct |
4 ms |
8540 KB |
Output is correct |
7 |
Correct |
4 ms |
8540 KB |
Output is correct |
8 |
Correct |
5 ms |
8540 KB |
Output is correct |
9 |
Correct |
5 ms |
8536 KB |
Output is correct |
10 |
Correct |
4 ms |
8536 KB |
Output is correct |
11 |
Correct |
5 ms |
8540 KB |
Output is correct |
12 |
Correct |
4 ms |
8536 KB |
Output is correct |
13 |
Correct |
4 ms |
8540 KB |
Output is correct |
14 |
Correct |
4 ms |
8540 KB |
Output is correct |
15 |
Correct |
4 ms |
8540 KB |
Output is correct |
16 |
Correct |
4 ms |
8576 KB |
Output is correct |
17 |
Correct |
5 ms |
8536 KB |
Output is correct |
18 |
Correct |
4 ms |
8536 KB |
Output is correct |
19 |
Correct |
3 ms |
8540 KB |
Output is correct |
20 |
Correct |
4 ms |
8540 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
8536 KB |
Output is correct |
2 |
Correct |
4 ms |
8536 KB |
Output is correct |
3 |
Correct |
4 ms |
8540 KB |
Output is correct |
4 |
Correct |
4 ms |
8540 KB |
Output is correct |
5 |
Correct |
4 ms |
8540 KB |
Output is correct |
6 |
Correct |
4 ms |
8540 KB |
Output is correct |
7 |
Correct |
4 ms |
8540 KB |
Output is correct |
8 |
Correct |
5 ms |
8540 KB |
Output is correct |
9 |
Correct |
5 ms |
8536 KB |
Output is correct |
10 |
Correct |
4 ms |
8536 KB |
Output is correct |
11 |
Correct |
5 ms |
8540 KB |
Output is correct |
12 |
Correct |
4 ms |
8536 KB |
Output is correct |
13 |
Correct |
4 ms |
8540 KB |
Output is correct |
14 |
Correct |
4 ms |
8540 KB |
Output is correct |
15 |
Correct |
4 ms |
8540 KB |
Output is correct |
16 |
Correct |
4 ms |
8576 KB |
Output is correct |
17 |
Correct |
5 ms |
8536 KB |
Output is correct |
18 |
Correct |
4 ms |
8536 KB |
Output is correct |
19 |
Correct |
3 ms |
8540 KB |
Output is correct |
20 |
Correct |
4 ms |
8540 KB |
Output is correct |
21 |
Execution timed out |
2040 ms |
8540 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
71 ms |
17016 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
8536 KB |
Output is correct |
2 |
Correct |
4 ms |
8536 KB |
Output is correct |
3 |
Correct |
4 ms |
8540 KB |
Output is correct |
4 |
Correct |
4 ms |
8540 KB |
Output is correct |
5 |
Correct |
4 ms |
8540 KB |
Output is correct |
6 |
Correct |
4 ms |
8540 KB |
Output is correct |
7 |
Correct |
4 ms |
8540 KB |
Output is correct |
8 |
Correct |
5 ms |
8540 KB |
Output is correct |
9 |
Correct |
5 ms |
8536 KB |
Output is correct |
10 |
Correct |
4 ms |
8536 KB |
Output is correct |
11 |
Correct |
5 ms |
8540 KB |
Output is correct |
12 |
Correct |
4 ms |
8536 KB |
Output is correct |
13 |
Correct |
4 ms |
8540 KB |
Output is correct |
14 |
Correct |
4 ms |
8540 KB |
Output is correct |
15 |
Correct |
4 ms |
8540 KB |
Output is correct |
16 |
Correct |
4 ms |
8576 KB |
Output is correct |
17 |
Correct |
5 ms |
8536 KB |
Output is correct |
18 |
Correct |
4 ms |
8536 KB |
Output is correct |
19 |
Correct |
3 ms |
8540 KB |
Output is correct |
20 |
Correct |
4 ms |
8540 KB |
Output is correct |
21 |
Execution timed out |
2040 ms |
8540 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |