Dkarampi solution

[dkarampi]

Check List:

• [X ] Tests pass (./test.sh <username> shows no differences between expected and actual outputs)

• [X] All formatting changes by the build are committed

• [X] Your launch script is named calculate_average_<username>.sh (make sure to match casing of your GH user name) and is executable

• [X] Output matches that of calculate_average_baseline.sh

• [X] For new entries, or after substantial changes: When implementing custom hash structures, please point to where you deal with hash collisions (line number)

• Execution time: 9.6sec

• Execution time of reference implementation: 2m 14.9sec

[gunnarmorling]

Please run the formatter via mvn verify and amend this PR with any changes it makes.

[dkarampi]

Done!

[gunnarmorling]

00:17.046.