#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define pb emplace_back
#define lb(v,k) (lower_bound(all(v),(k))-v.begin())
#define ub(v,k) (upper_bound(all(v),(k))-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define all(a) a.begin(),a.end()
#define rsort(a) {sort(all(a));reverse(all(a));}
#define dupli(a) {sort(all(a));a.erase(unique(all(a)),a.end());}
#define popcnt __builtin_popcountll
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vvvvi=vector<vvvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const ll INF=1001001001;
const ll mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void outset(T s){auto itr=s.begin();while(itr!=s.end()){if(itr!=s.begin())cout<<' ';cout<<*itr;itr++;}cout<<'\n';}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}
int main(){
ll n;cin>>n;
vp v(n);
vi srt;
rep(i,n){
cin>>v[i].fi>>v[i].se;v[i].se++;
srt.pb(v[i].fi);
srt.pb(v[i].se);
}
dupli(srt);
rep(i,n){
v[i].fi=lb(srt,v[i].fi);
v[i].se=lb(srt,v[i].se);
}
ll m=srt.size();
vvi dp(m,vi(n+1)),table(m-1,vi(n+1));
vi inv(n+5);REP(i,1,n+5)inv[i]=modpow(i,mod-2);
rep(i,m-1){
ll x=(srt[i+1]-srt[i])%mod;
table[i][0]=x;
REP(j,1,n+1){
ll tmp=x*(x-1)/2%mod;
rep(k,j){
table[i][j]+=tmp;
tmp*=(j-1-k)*inv[k+1]%mod*(x-k-2)%mod*inv[k+3]%mod;
tmp%=mod;
}
table[i][j]%=mod;
}
}
rep(i,m)dp[i][0]=1;
rep(j,n+1)dp[0][j]=1;
REP(i,1,m)REP(j,1,n+1){
dp[i][j]=dp[i-1][j]+dp[i][j-1]-dp[i-1][j-1];
if(i-1<v[j-1].fi||v[j-1].se<=i-1)continue;
ll cnt=0;
for(int k=j;k;k--){
if(i-1<v[k-1].fi||v[k-1].se<=i-1)continue;
dp[i][j]+=table[i-1][cnt++]*dp[i-1][k-1]%mod;
}
dp[i][j]%=mod;
}
// outvv(dp);
if(dp[m-1][n]<=0)dp[m-1][n]+=mod;
out(dp[m-1][n]-1);
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1006 ms |
8260 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1006 ms |
8260 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
11 ms |
620 KB |
Output is correct |
| 2 |
Correct |
10 ms |
628 KB |
Output is correct |
| 3 |
Correct |
10 ms |
588 KB |
Output is correct |
| 4 |
Incorrect |
11 ms |
620 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1006 ms |
8260 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
