#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vii;
typedef long double ld;
typedef pair<ll,ll> pii;
#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define all(v) v.begin(),v.end()
#define pow poww
const ll M=1e6+10;
const ll inf=2e18;
const ll mod=1e9+7;
ll pow(ll x,ll y){
ll res=1;
x%=mod;
while(y>0){
if((y&1))
res*=x,res%=mod;
x*=x,x%=mod;
y=(y>>1);
}
return res;
}
ll sz=1;
struct seg{
vii a;
void init(ll x){
while(sz<x)
sz*=2;
a.resize(sz*2);
}
void update(ll i,ll v,ll x=0,ll lx=0,ll rx=sz){
if(rx-lx==1){
a[x]=v;
return;
}
ll mid=((lx+rx)>>1);
if(i<mid)
update(i,v,x*2+1,lx,mid);
else
update(i,v,x*2+2,mid,rx);
a[x]=max(a[x*2+1],a[x*2+2]);
}
ll query(ll l,ll r,ll x=0,ll lx=0,ll rx=sz){
if(r==l)
return 0;
if(lx>=l&&rx<=r)
return a[x];
if(lx>=r||rx<=l)
return 0;
ll mid=((lx+rx)>>1);
return max(query(l,r,x*2+1,lx,mid),query(l,r,x*2+2,mid,rx));
}
}s,ss[2];
ll n,f[M],ind[M];
bool dis[M];
pii a[M];
set<ll>v[M];
int main(){
ios_base::sync_with_stdio(0),cin.tie(0);
int TC=1;
//cin>>TC;
while(TC--){
cin>>n;
s.init(2*n);
ss[0].init(n),ss[1].init(n);
for(int i=0;i<n;i++){
cin>>a[i].F>>a[i].S,f[a[i].S]=a[i].F,ind[a[i].S]=ind[a[i].F]=i;
}
ll ans=n;
sort(a,a+n);
for(int i=0;i<n;i++){
s.update(a[i].F,a[i].S);
}
ss[0].update(1,a[0].S);
for(int i=0;i<n;i++){
while(1){
ll x=s.query(a[i].F+1,a[i].S);
if(x<a[i].S)
break;
else{
s.update(f[x],0);
dis[ind[x]]=1-dis[i];
ss[dis[ind[x]]].update(f[x],x);
ans--;
v[i].insert(ind[x]);
}
}
}
for(int i=0;i<n;i++){
ll x=ss[dis[i]].query(a[i].F+1,a[i].S);
if(x>a[i].S){
ans=0;
}
}
if(ans==0)
cout<<0<<'\n';
else
cout<<pow(2,ans)<<'\n';
}
return 0;
}
/*
*/
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
29 ms |
51804 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
29 ms |
51804 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
29 ms |
51804 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
29 ms |
51804 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
