Factors of an integer
You are encouraged to solve this task according to the task description, using any language you may know.
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
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Integer Operations
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Compute the factors of a number.
See also Prime decomposition
Clojure
<lang lisp>(defn factors [n] (filter #(zero? (rem n %)) (range 1 n)))
(print (factors 45))</lang>
(1 3 5 9 15)
Python
<lang python>>>> def factors(n): return [i for i in range(1,n//2) if not n%i]
>>> factors(45) [1, 3, 5, 9, 15]</lang>
Ruby
<lang ruby>class Integer
def factors() (1..self).select { |n| (self % n).zero? } end
end p 45.factors</lang>
[1, 3, 5, 9, 15, 45]
As we only have to loop up to , we can write <lang ruby>class Integer
def factors()
1.upto(Math.sqrt(self)).select {|i| (self % i).zero?}.inject([]) do |f, i|
f << i
f << self/i unless i == self/i
f
end.sort
end
end [45, 53, 64].each {|n| p n.factors}</lang> output
[1, 3, 5, 9, 15, 45] [1, 53] [1, 2, 4, 8, 16, 32, 64]
Tcl
<lang tcl>proc factors {n} {
set factors {}
for {set i 1} {$i <= sqrt($n)} {incr i} {
if {$n % $i == 0} {
lappend factors $i [expr {$n / $i}]
}
}
return [lsort -unique -integer $factors]
} puts [factors 64] puts [factors 45] puts [factors 53]</lang> output
1 2 4 8 16 32 64 1 3 5 9 15 45 1 53