运用费马小定理&&矩阵快速幂 求出 a , b 的个数
运用快速幂求解 a^num1 * b ^ num2 % MOD
#include
#include
typedef __int64 LL;
#define MOD 1000000007
#define mod 1000000006
struct matrix//矩阵
{
LL Matrix[2][2];
};
matrix s =
{
1,1,
1,0,
};
matrix m =
{
1,0,
0,1,
};
matrix matrix_multiplication(matrix a,matrix b)//矩阵乘法
{
matrix c;
for(int i = 0;i < 2;i ++)
{
for(int j =0;j < 2;j++)
{
c.Matrix[i][j] = 0;
for(int k = 0;k < 2;k++)
c.Matrix[i][j] = (c.Matrix[i][j] + a.Matrix[i][k]*b.Matrix[k][j]) % mod;
}
}
return c;
}
matrix Fast_power1(LL n)//矩阵快速幂
{
matrix ret = m,p = s;
while(n)
{
if(n&1) ret = matrix_multiplication(ret,p);
p = matrix_multiplication(p,p);
n >>= 1;
}
return ret;
}
LL Fast_power2(LL x,LL num)//x^num%MOD的快速幂
{
LL res = 1;
while(num)
{
if(num&1) res = (res * x) % MOD;
x = (x*x)%MOD;
num>>=1;
}
return res;
}
int main()
{
LL a,b,n,x,y;
while(~scanf("%I64d%I64d%I64d",&a,&b,&n))
{
matrix k;
k = Fast_power1(n);
LL x = k.Matrix[1][1],y = k.Matrix[1][0];
LL z = (Fast_power2(a,x) * Fast_power2(b,y))%MOD;
printf("%I64d\n",z);
}
}