Primality by trial division: Difference between revisions

=={{header|BCPL}}==

<lang bcpl>get "libhdr"

let sqrt(s) =

s <= 1 -> 1,

valof

$( let x0 = s >> 1

let x1 = (x0 + s/x0) >> 1

while x1 < x0

$( x0 := x1

x1 := (x0 + s/x0) >> 1

$)

resultis x0

$)

let isprime(n) =

n < 2 -> false,

(n & 1) = 0 -> n = 2,

valof

$( for i=3 to sqrt(n)

if n rem i = 0 resultis false

resultis true

$)

let start() be

$( for i=1 to 100

if isprime(i) then writef("%N ",i)

wrch('*N')

$)</lang>

{{out}}

<pre>2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97</pre>