Scheduling jobs based on dependencies.
Imagine we have a list of jobs, each represented by a character. Because certain jobs must be done before others, a job may have a
dependency on another job. For example, a may depend on b, meaning the final sequence of jobs should place b before a. If a has no
dependency, the position of a in the final sequence does not matter.
Given you’re passed an empty string (no jobs), the result should be an empty sequence.
Given the following job structure:
a =>
The result should be a sequence consisting of a single job a.
Given the following job structure:
a =>
b =>
c =>
The result should be a sequence containing all three jobs abc in no significant order.
Given the following job structure:
a =>
b => c
c =>
The result should be a sequence that positions c before b, containing all three jobs abc.
Given the following job structure:
a =>
b => c
c => f
d => a
e => b
f =>
The result should be a sequence that positions f before c, c before b, b before e and a before d containing all six jobs abcdef.
Given the following job structure:
a =>
b =>
c => c
The result should be an error stating that jobs can’t depend on themselves.
Given the following job structure:
a =>
b => c
c => f
d => a
e =>
f => b
The result should be an error stating that jobs can’t have circular dependencies.