#include <bits/stdc++.h>
using namespace std;
#define dbgv(v) cout<<#v<<" = "; f(i,0,v.size()) cout<<v[i]<<" "; cout<<endl
#define dbga(a,x,y) cout<<#a<<" = "; f(i,x,y) cout<<a[i]<<" "; cout<<endl
#define erorp(x) cout<<#x<<"={"<<x.F<<" , "<<x.S<<"}"<<endl
#define eror(x) cout<<#x<<'='<<(x)<<endl
#define f_(i,a,b) for(int i=a;i>=b;i--)
#define f(i,a,b) for(int i=a;i<b;i++)
#define nb(x) __builtin_popcount(x)
#define all(v) v.begin(),v.end()
#define bit(n,k) (((n)>>(k))&1)
#define Add(x,y) x=(x+y)%mod
#define maxm(a,b) a=max(a,b)
#define minm(a,b) a=min(a,b)
#define lst(x) x[x.size()-1]
#define sz(x) int(x.size())
#define mp make_pair
#define ll long long
#define pb push_back
#define S second
#define F first
//#include "horses.h"
const int N=5e5+99,mod=1e9+7;
const ll inf=1e18+mod;
ll n,t,a[N],b[N],L[N],R[N],seg[N<<1];
ll pd=1;
set<int> s;
ll pow(ll x,ll y,ll mod){return(!y?1:pow(x*x%mod,y/2,mod)*(y&1?x:1))%mod;}
void build(){
f(i,0,n) seg[i+n]=b[i];
f_(i,n-1,1) seg[i]=max(seg[i<<1],seg[i<<1|1]);
}
void update(int id,int val){
seg[id]=val;
for(id>>=1;id>0;id>>=1){
seg[id]=max(seg[id<<1],seg[id<<1|1]);
}
}
ll get(int l,int r){
ll ans=0;
for(l+=n,r+=n;l<r;l>>=1,r>>=1){
if(l&1) maxm(ans,seg[l++]);
if(r&1) maxm(ans,seg[--r]);
}
return ans;
}
int solve(){
ll ans=1,res=pd;
f(i,0,n) s.insert(i);
build();
for(int i=*s.rbegin();;i=*prev(s.lower_bound(i))){{
maxm(ans,a[i]*max(ans,get(i,n)));
res=1ll*res*pow(a[i],mod-2,mod)%mod;
if(i==0 || ans>mod) break;
}
ans%=mod;
return 1ll*res*ans%mod;
}
int init(int _n, int X[], int Y[]) {
n=_n;
f(i,0,n) a[i]=X[i];
f(i,0,n) b[i]=Y[i];
f(i,0,n){
pd=1ll*pd*a[i]%mod;
if(a[i]>1) s.insert(i);
}
build();
return solve();
}
int updateX(int pos, int val) {
if(a[pos]==1 && val!=1) s.insert(pos);
if(a[pos]!=1 && val==1) s.erase(pos);
pd=1ll*pd*pow(a[pos],mod-2,mod)%mod;
a[pos]=val;
pd=1ll*pd*a[pos]%mod;
return solve();
}
int updateY(int pos, int val) {
b[pos]=val;
update(pos+n,val);
return solve();
}
/*
int32_t main(){
ios:: sync_with_stdio(0), cin.tie(0), cout.tie(0);
int n,q,a[10],b[10];
cin>>n;
f(i,0,n) cin>>a[i];
f(i,0,n) cin>>b[i];
cout<<init(n,a,b)<<endl;
cin>>q;
while(q--){
int t,pos,val;
cin>>t>>pos>>val;
if(t==1) cout<<updateX(pos,val)<<endl;
else cout<<updateY(pos,val)<<endl;
}
}*/
/*
3
2 1 3
3 4 1
1
2 1 2
*/
Compilation message
horses.cpp: In function 'long long int pow(long long int, long long int, long long int)':
horses.cpp:31:21: warning: declaration of 'mod' shadows a global declaration [-Wshadow]
31 | ll pow(ll x,ll y,ll mod){return(!y?1:pow(x*x%mod,y/2,mod)*(y&1?x:1))%mod;}
| ^
horses.cpp:24:20: note: shadowed declaration is here
24 | const int N=5e5+99,mod=1e9+7;
| ^~~
horses.cpp: In function 'void build()':
horses.cpp:35:8: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
35 | f_(i,n-1,1) seg[i]=max(seg[i<<1],seg[i<<1|1]);
| ~^~
horses.cpp:7:29: note: in definition of macro 'f_'
7 | #define f_(i,a,b) for(int i=a;i>=b;i--)
| ^
horses.cpp: In function 'long long int get(int, int)':
horses.cpp:45:7: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
45 | for(l+=n,r+=n;l<r;l>>=1,r>>=1){
| ~^~~
horses.cpp:45:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
45 | for(l+=n,r+=n;l<r;l>>=1,r>>=1){
| ~^~~
horses.cpp: In function 'int solve()':
horses.cpp:56:31: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
56 | maxm(ans,a[i]*max(ans,get(i,n)));
| ^
horses.cpp:13:27: note: in definition of macro 'maxm'
13 | #define maxm(a,b) a=max(a,b)
| ^
horses.cpp:61:20: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
61 | return 1ll*res*ans%mod;
| ~~~~~~~~~~~^~~~
horses.cpp:63:36: error: a function-definition is not allowed here before '{' token
63 | int init(int _n, int X[], int Y[]) {
| ^
horses.cpp:74:31: error: a function-definition is not allowed here before '{' token
74 | int updateX(int pos, int val) {
| ^
horses.cpp:82:31: error: a function-definition is not allowed here before '{' token
82 | int updateY(int pos, int val) {
| ^
horses.cpp:86:1: error: expected '}' at end of input
86 | }
| ^
horses.cpp:51:12: note: to match this '{'
51 | int solve(){
| ^
horses.cpp:86:1: warning: control reaches end of non-void function [-Wreturn-type]
86 | }
| ^
