Fibonacci fast power matrix template

0.0 Templates for personal use

Fibonacci numbers deed Detailed method for finding a variety of direct poke here here Wallpaper (chiefs to explain in great detail)

---

typedef long long ll;
#define mod 1000000007
struct mat
{
	ll a[2][2];
}ans;
mat multi(mat m,mat n)
{
	mat temp;
	for(int i=0;i<2;i++)
		for(int j=0;j<2;j++)
		{
			temp.a[i][j]=0;
			for(int k=0;k<2;k++)
			{
				temp.a[i][j]=(temp.a[i][j]+m.a[i][k]%mod*n.a[k][j]%mod)%mod;
			}
		}
	return temp;
}
ll multi_pow(int b)
{
	mat tem;
	tem.a[0][0]=tem.a[0][1]=tem.a[1][0]=1;
	tem.a[1][1]=0;
	ans.a[0][0]=ans.a[1][1]=1;
	ans.a[0][1]=ans.a[1][0]=0;
	while(b)
	{
		if(b&1)
			ans=multi(ans,tem);
		b>>=1;
		tem=multi(tem,tem);
	}
	return ans.a[0][1];
}