int multiply(int a[],int low,int high,int modulus)
{
if(low==high)
return (a[low]);
else
{
int mid = (low+high)/2;
int x = multiply(a, low, mid, modulus) % modulus;
int y = multiply(a, mid+1, high, modulus) % modulus;
return ((x*y) % modulus);
}
}
它的时间复杂度是 O(log n) 还是 O(n) ?
请帮我。