#include <iostream>
#include <unordered_map>
#include <map>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> pll;
ll M=1000000007;
int N;
ll X[505],Y[505];
vector<ll> DP[505];
ll ans;
ll R[4000006];
unordered_map<ll,ll> L;
vector<ll> V;
ll query(ll k, ll l, ll r, ll a, ll b){
if(b<l or r<a) return 0;
if(a<=l and r<=b) return R[k];
ll m=(l+r)/2;
return (query(2*k,l,m,a,b)+query(2*k+1,m+1,r,a,b))%M;
}
void insert(ll k, ll l, ll r, ll a, ll b){
if(l==r) R[k]=(R[k]+b)%M;
else{
ll m=(l+r)/2;
if(a<=m)
insert(2*k,l,m,a,b);
else
insert(2*k+1,m+1,r,a,b);
R[k]=(R[2*k]+R[2*k+1])%M;
}
}
ll somma(ll a){
return query(1,0,1e6+1,a,1e6);
}
void aggiungi(ll a, ll b){
insert(1,0,1e6,a,b);
}
int main(){
cin>>N;
for(int i=0;i<N;i++)
cin>>X[i]>>Y[i];
for(int i=0;i<N;i++)
DP[i].resize(Y[i]-X[i]+2);
for(int i=0;i<N;i++)
for(int j=X[i];j<Y[i]+1;j++)
V.push_back(j);
sort(V.begin(),V.end());
ll p=0;
for(int i=0;i<V.size();i++)
if(i==0 or V[i]!=V[i-1])
L[V[i]]=p++;
for(int i=N-1;i>=0;i--)
for(ll j=X[i],k=0;j<=Y[i];j++,k++){
DP[i][k]=(somma(L[j+1])+1)%M;
aggiungi(L[j],DP[i][k]);
ans=(ans+DP[i][k])%M;
//cout<<i<<" "<<j<<" "<<DP[{i,j}]<<endl;
}
//for(int i=0;i<10;i++)cout<<i<<" "<<S[i]<<endl;
cout<<ans;
}
/*
3
1 1
2 2
3 3
*/
/*
8
10000 30000
20000 40000
30000 50000
40000 60000
50000 70000
60000 80000
70000 90000
80000 100000
*/
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:68:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<V.size();i++)
~^~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
4 ms |
500 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
4 ms |
500 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
7 ms |
872 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
4 ms |
500 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |