Download or view allFactors.frink in plain text format
// This function finds all divisors of a number, including 1 and the number
// itself. This version uses the "multifor" construct to simplify the logic.
allFactors[n, include1=true, includeN=true, sort=true, onlyToSqrt=false] :=
{
if n == 1
if include1 or includeN
return [1]
else
return []
factors = factor[n]
size = length[factors]
if onlyToSqrt == false
upperLimit = n
else
upperLimit = floor[sqrt[n]]
/* We can precalculate the size of the results. Each base in the factor
list multiplies the total factors by exp+1 */
resultSize = 1
for [base,exp] = factors
resultSize = resultSize * (exp+1)
results = new array[resultSize]
loops = new array[size]
for [base,count] = factors
loops.push[new range[0,count]]
multifor c = loops
{
product = 1
for i = 0 to length[c]-1
product = product * (factors@i@0)^(c@i)
if (product > upperLimit)
next
if ((product == 1 and include1 == false) or (product == n and includeN == false))
{
// Do nothing
} else
results.push[product]
}
if sort
sort[results] // Sorts in place
return results
}
"allFactors included successfully."
Download or view allFactors.frink in plain text format
This is a program written in the programming language Frink.
For more information, view the Frink
Documentation or see More Sample Frink Programs.
Alan Eliasen, eliasen@mindspring.com