1289. 序列的第k个数快速幂

Posted 2021-11-04 幽殇默

https://www.acwing.com/problem/content/1291/

#include<bits/stdc++.h>
using namespace std;
typedef long long int unsigned LL;
const int mod=200907;
LL t,a,b,c,k;
LL quick_mi(LL a,LL b, LL p)
{
    LL sum=1;
    while(b)
    {
        if(b&1) sum=sum*a%p;
        b>>=1;
        a=(a*a)%p;
    }
    return sum%p;
}
int main(void)
{
    cin>>t;
    while(t--)
    {
        cin>>a>>b>>c>>k;
        if(b-a==c-b) cout<<(a+(k-1)*(b-a))%mod<<endl;
        else  cout<<a*quick_mi(b/a,k-1,mod)%mod<<endl;
    }
    return 0;
}