FA-96165 / Postal address normalization / Member archive

Delivery point check digit: missing house number defaults to 00 · case 05

A line without house digits gets delivery point 00.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

Input [zip5, plus4, primary]. The delivery point is the last two of the leading digits of the primary number, zero-padded to two, or "99" when there are none. With a plus-four the digit string is zip5 + plus4 + delivery point, otherwise zip5 alone. Append the check digit (10 - digit sum mod 10) mod 10.

Why this case matters

A wrong delivery point or check digit sends machine-sorted mail to the wrong door or rejects it.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
no house digits uses the default	`"567456789003"`	`"567456789995"`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.