Anonymous user
Damm algorithm: Difference between revisions
→{{header|Nim}}
Line 880:
=={{header|Nim}}==
<lang Nim>
from algorithm import reverse
const Table = [[0, 3, 1, 7, 5, 9, 8, 6, 4, 2],
[7, 0, 9, 2, 1, 5, 4, 8, 6, 3],
[4, 2, 0, 6, 8, 7, 1, 3, 5, 9],
[1, 7, 5, 0, 9, 8, 3, 4, 2, 6],
[6, 1, 2, 3, 0, 4, 5, 9, 7, 8],
[3, 6, 7, 4, 2, 0, 9, 5, 8, 1],
[5, 8, 6, 9, 7, 2, 0, 1, 3, 4],
[8, 9, 4, 5, 3, 6, 2, 0, 1, 7],
[9, 4, 3, 8, 6, 1, 7, 2, 0, 5],
[2, 5, 8, 1, 4, 3, 6, 7, 9, 0]]
type Digit = range[0..9]
func isValid(digits: openArray[Digit]): bool =
## Apply Damm algorithm to check validity of a digit sequence.
var interim = 0
for d in digits:
interim = Table[interim][d]
result = interim == 0
proc toDigits(n: int): seq[Digit] =
## Return the digits of a number.
var n = n
while true:
result.add(n mod 10)
n = n div 10
if n == 0:
break
result.reverse()
proc checkData(digits: openArray[Digit]) =
## Check if a digit sequence if valid.
if isValid(digits):
echo "Sequence ", digits, " is valid."
else:
echo "Sequence ", digits, " is invalid."
checkData(5724.toDigits)
checkData(5727.toDigits)
checkData([Digit 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 6, 7, 8, 9, 0, 1])
checkData([Digit 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 6, 7, 8, 9, 0, 8])
</lang>
=={{out}}==
<pre>
Sequence [5, 7, 2, 4] is valid.
Sequence [5, 7, 2, 7] is invalid.
Sequence [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 6, 7, 8, 9, 0, 1] is valid.
Sequence [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 6, 7, 8, 9, 0, 8] is invalid.
</pre>
=={{header|Objeck}}==
| |||