simplemath

func Add ¶

func Add(a, b uint) (uint, error)

Add returns the sum of a and b if no numeric overflow occurs, or an error otherwise.

func Factorial ¶

func Factorial(n uint) (uint, error)

Factorial returns the factorial of n, or 1 for n=0. Error is reported if numeric overflow occurs.

func Mul ¶

func Mul(a, b uint) (uint, error)

Mul returns the product of a and b, or an error if numeric overflow occurs.

func MulRange ¶

func MulRange(n2, n1 uint) (r uint, err error)

MulRange calculates the product of all integers within the inclusive interval [n1, n2] (or [n2, n1] if n2 < n1).

It returns the product if no numeric overflow occurs. Otherwise, it returns an error, and the partial product calculated before the overflow is stored in 'r'.

func NumComb ¶

func NumComb(n, k uint) (uint, error)

NumComb calculates the number of combinations for the specified k and n.

n: number of elements to combine; n>=k must hold. k: number of elements in a combination.

Error is reported if numeric overflow occurs.