larsmelander/match-intervals

Programming task

Find matching intervals

A common problem our customers have is that they have a list of when they need employees to work and the employees in turn have their availability when they CAN work. Given the input of vacant shifts and a list of availability for a single employee, write a program that outputs a list of all shifts that match the availability. Shifts may overlap and it is up to customer to then choose which shifts to finally book.

For example:

Given the following vacant shifts:

Shift A1C: 2019-10-28 08:00 - 2019-10-28 17:00
Shift RR4: 2019-10-28 11:00 - 2019-10-28 20:00
Shift CD1: 2019-10-28 14:00 - 2019-10-28 23:00

And the following availability for an employee:

Availability 5E8: 2019-10-28 09:00 - 2019-10-28 23:00

It gives that two shifts could be booked:

RR4
CD1

Input and output

The program should read its input data from stdin and output the result to stdout. The input data has the following format:

<input-data>      ::= <input-row> | <input-row> <input-data>
<input-row>       ::= <type-identifier> <row-id>":" <from-date> <from-time> "-" <to-date> <to-time> <EOL>
<type-identifier> ::= "Shift" | "Availability"
<row-id>          ::= ([0-9a-zA-Z]+)
<from-date>       ::= YYYY-mm-dd
<from-time>       ::= HH:MM
<to-date>         ::= YYYY-mm-dd
<to-time>         ::= HH:MM

The type-identifier can be either Shift or Availability. The row-id can be any combination of English alpha-numeric characters ([0-9a-zA-Z]+). The from-date and to-date are both dates in ISO format. Both time fields are formatted as HH:MM. The input rows will not come in any particular order and shift rows and availability rows may be interleaved.

The program should output a newline-separated list of Shift IDs that are possible to book given the availability.

Program structure

The program should be written in Javascript and be compatible with Node.JS version 12. You can clone this repository to get a skeleton structure where you can add your code in src/index.js and then run the project with

npm start

Test data

Test data can be found in the file input-data.txt.