include
# include <math.h>
using namespace std;
void multiply(int F[2][2], int M[2][2]);
void power(int F[2][2], int n);
int fib(int n)
{
int F[2][2] = {{1,1},{1,0}};
if (n == 0)
return 0;
power(F, n-1);
return F[0][0]%1000000007;
}
void power(int F[2][2], int n)
{
if( n == 0 || n == 1)
return;
int M[2][2] = {{1,1},{1,0}};
power(F, n/2);
multiply(F, F);
if (n%2 != 0)
multiply(F, M);
}
void multiply(int F[2][2], int M[2][2])
{
int x = F[0][0]*M[0][0] + F[0][1]*M[1][0];
int y = F[0][0]*M[0][1] + F[0][1]*M[1][1];
int z = F[1][0]*M[0][0] + F[1][1]*M[1][0];
int w = F[1][0]*M[0][1] + F[1][1]*M[1][1];
F[0][0] = x;
F[0][1] = y;
F[1][0] = z;
F[1][1] = w;
}
int main()
{long long i,n,x,sum=0,t=0;
cin>>i;
while(i--)
{
cin>>n>>x;
sum=(fib(n-1)*pow(x,n+2))+((fib(n)*pow(x,n+1))-x);
t=(x*x)+x-1;
cout<<(((sum/t)%1000000007)%1000000007)<<endl;
}
}
meooow
3
This is just at a glance, but you’re not performing the calculations under modulo inside the multiply
function.
1 Like
constraints are:
1 ≤ T ≤ 1000
0 ≤ n ≤ 10^15
0 ≤ x ≤ 10^15
use long long instead of int,
Reference solution, please explain the approach you are applying to solve this problem.