languages

luhn algorithm

function luhn_test ([string]$cardNoStr) {

$s=$cardNoStr

$f=1

$r=@(0..($s.length-1))

for ($i = 0; $i -le ($s.length - 1); $i += 1) {

$r[$i]=$f*(($s[$s.length-$i-1])-([char]"0"))

$f=3-$f

}

$nsum=0

for ($i = 0; $i -le ($r.length - 1); $i += 1) {

$nsum=$nsum + [int][Math]::Floor($r[$i]/10) + $r[$i] % 10

}

('fail','pass')[1-[int](($nsum % 10 -ne 0))]

}

luhn_test "1234567812345670"

quick sort

luhn algorithm

luhn algorithm

[[.card|explode|(.[]-48)] | reverse | map (tonumber) 

,([range(0,length)] |map(.%2+1))  ]|transpose | map(.[0]*.[1])

|map(.%10+./10|trunc)|add| if .%10==0 then true else false end