Multiplication Method

h(k) = , where 0<A<1

(kA mod 1) returns the fractional part of kA.

In this case the choice of m is less critical. Typically choose a power of 2 to simplify arithmetic.

However, the choice of A does matter. A recommendation is to use

$$A \;=\; \frac{\sqrt{5} - 1}{2} \;=\; 0.6180339887 ...$$

The worst choice is A = 0.5, because in this case every key hashes to or 0.