HDU 4549 (费马小定理+矩阵快速幂+二分快速幂)

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#define mod  1000000006
#define mod2 1000000007
typedef long long ll;
struct matrix
{
    ll data[2][2];
};
matrix I= {1,0,0,1};
matrix multi(matrix a,matrix b)
{
    matrix c;
    memset(c.data,0,sizeof(c.data));
    for(int i=0; i<2; i++)
        for(int j=0; j<2; j++)
            for(int k=0; k<2; k++)
            {
                c.data[i][j]+=(a.data[i][k]%mod)*(b.data[k][j]%mod);
                c.data[i][j]%=mod;
            }
    return c;
}
matrix pow(matrix a,ll b)
{
    matrix ans=I;
    while(b)
    {
        if(b&1)
        {
            ans=multi(ans,a);
            b--;
        }
        b>>=1;
        a=multi(a,a);
    }
    return ans;
}
ll pow2(ll a,ll b)
{
    ll ans=1;
    while(b)
    {
        if(b&1)
        {
            ans*=a;
            ans%=mod2;
            b--;
        }
        b>>=1;
        a*=a;
        a%=mod2;
    }
    return ans;
}
int main()
{
    ll aa,bb,an,bn,n;
    while(scanf("%lld%lld%lld",&aa,&bb,&n)!=EOF)
    {
        matrix a= {1,1,1,0};
        matrix ans;
        ans=pow(a,n);
        bn=ans.data[0][1];
        an=ans.data[1][1];
        //cout<<"a: "<<an<<"  b: "<<bn<<endl;
        ll ans2=((pow2(aa,an)%mod2)*(pow2(bb,bn)%mod2))%mod2;
        printf("%lld\n",ans2);
    }
    return 0;
}