#include"gondola.h"
#include<bits/stdc++.h>
//#include"grader.cpp"
using namespace std;
typedef long long int ll;
ll mod=1e9+7;
int valid(int n,int a[]){
int i=0,need;
while(i<n&&a[i]>n)i++;
need=a[i];
while(i<n){
if(a[i]<=n&&a[i]!=need)return 0;
if(need==n)need=1;
else need++;
i++;
}
sort(a,a+n);
for(i=1;i<n;i++)if(a[i]==a[i-1])return 0;
return 1;
}
int replacement(int n,int a[],int res[]){
vector<pair<int,int>>b;
int i=0,ind=n,need=1,len=0,x;
while(i<n&&a[i]>n)i++;
if(i!=n)need=a[i]-i;
if(need<1)need+=n;
for(i=0;i<n;i++,need=need%n+1)b.push_back({a[i],need});
sort(b.begin(),b.end());
i=0;
while(i<n){
if(b[i].first<=n){
i++;
continue;
}
res[len++]=b[i].second;
x=++ind;
while(x!=b[i].first){
res[len++]=x;
x=++ind;
}
i++;
}
return len;
}
ll pw(ll a,ll b){
if(!b)return 1;
if(b&1)return (1ll*a*pw(a,b-1))%mod;
ll x=pw(a,b>>1ll);
return (1ll*x*x)%mod;
}
int countReplacement(int n, int inputSeq[])
{
if(!valid(n,inputSeq))return 0;
int i,r=1;
sort(inputSeq,inputSeq+n);
for(i=0;i<n;i++)
{
if(inputSeq[i]<=n)continue;
r=1LL*r*pw(n-i,inputSeq[i]-(i>0?max(inputSeq[i-1],n):n)-1)%mod;
}
return 1LL*r*(inputSeq[0]>n?n:1)%mod;
}
