Validating a CPR number

Question

Validating a CPR number

A Danish CPR number (Person Identification Number) is date of birth followed by 4 digits (the last one being a control digit): DDMMYY-XXXX

The final digit validates the CPR number using Modulo 11 by satisfying the following equation:

where the are the ten digits of the complete ID number, and the coefficients (4, 3, 2, 7, …) are all nonzero in the finite field of order 11.

Input

A CPR number formatted like this DDMMYY-XXXX where YY indicates a year within the last 100 years (between 1917 and 2016).

Output

Indication whether CPR number is valid (1 or true) or invalid (0 or false)

Examples

  290215-2353 --> false
  140585-2981 --> true
  311217-6852 --> true
  121200-0004 --> false
  140322-5166 --> false
  111111-1118 --> true

Scoring

This is code-golf - fewest bytes win!

Date validation

All years refer to a period within the last 100 years. A valid date is a date that exists within it's calendar year.

290215 is not a valid date because 29/2 wasn't a date in 2015.

301216 is a valid date because 30/12 is a date in 2016.

Answer 1

Python (2), 167 156 155 142 141 bytes

from time import*
def f(s):
 try:return 1>sum(int(i)*(ord(j)-48)for i,j in zip("43276504321",s))%11;strptime(s[:6],"%d%m%y")
 except:return 0

tried to do the date validation without the library, but it's 168 bytes:

lambda s:sum(int(i)*(ord(j)-48)for i,j in zip("43276504321",s))%11==0 and int(s[0:2])<([0,32,(29,30)[int(s[4:6])%4==0],32]+[31,32]*2+[32,31]*2+[32]+[0]*99)[int(s[2:4])]

-12 bytes thanks to @GáborFekete

-14 bytes thanks to @RootTwo

Answer 2

Ruby, 145 113 112 103 + 8 (-nrdate flags) = 111 bytes

Returns a date object (truthy) if it's a valid CPR, false if it fails the modulo test, and nil (falsy) if it fails the date test. Input is STDIN.

-33 bytes from @Jordan

s=0
$_.size.times{|i|s+=12340567234/10**i%10*$_[i].to_i}
p s%11<1&&Date.strptime($_,"%d%m%y")rescue p p

Version that returns literal true on valid CPR for +1 byte:

s=0
$_.size.times{|i|s+=12340567234/10**i%10*$_[i].to_i}
p Date.strptime($_,"%d%m%y")&&s%11<1 rescue p p

Version that returns an error on invalid date instead of nil, for -10 bytes but probably invalid:

s=0
$_.size.times{|i|s+=12340567234/10**i%10*$_[i].to_i}
p Date.strptime($_,"%d%m%y")&&s%11<1

Answer 3

Mathematica, 130 bytes

DateObject[a={10#5+#6+4,10#3+#4,10#+#2}][[1]]==a&&11∣Tr[{4,3,2,7,6,5,4,3,2,1}{##}]&@@IntegerDigits@FromDigits[#~StringDrop~{7}]&

Anonymous function. Takes a string as input and returns True or False as output. The Unicode character is U+2223 DIVIDES, representing \[Divides].

Answer 4

Ruby + GNU date, 112 111 103 bytes

-8 bytes from Kevin Lau.

->n{s=0
n.size.times{|i|s+=12340567234/10**i%10*n[i].to_i}
n=~/#{"(..)"*3}/
s%11<1&&`date -d#$3#$2#$1`>""}

Note that this prints e.g. "date: invalid date ‘150229’" to stderr if the date portion is invalid, but it still returns true or false (it doesn't raise an exception). If that's a disqualifier, though, I can add ⎵2>/dev/null for a 12-byte penalty.

Ungolfed

v = ->(cpr) {
  sum = 0

  cpr.size.times do |idx|
    sum += 12340567234 / 10**idx % 10 * cpr[idx].to_i
  end

  cpr =~ /#{"(..)" * 3}/
  sum % 11 < 1 && `date -d#$3#$2#$1` > ""
}