Function A

Function B

Function C

function isPrime$($number n$)$

for i from $2$ to square root of n rounded down inclusive

if n mod i is $0$

return false

return true

function isPrime$($number n$)$

factors $=$ generated array of numbers from $2$ to n$-1$ inclusive

for i in factors:

if n mod i is not equal to $0$

remove i from factors

if factors is not empty

return false

return true