快速幂模板

m^n%k 

m的n次方模k

int quickpow(int m,int n,int k)
{
	int b =1;
	while (n >0)
	{
		if (n &1)
			b = (b*m)%k;
		n = n >>1 ;
		m = (m*m)%k;
	}
	return b;
}