Done as part of a TDD exercise.

Get a string of one bowling game line, and return score.

Example: '20 00 X 1/ 03 04 00 00 00 70' should return: 46

There are 10 pines you try to knock down in each frame. A strike - knock all 10 pins with the first ball. A spare - knock all 10 pins with the second ball (2 throws). Each games consists of ten frames. If you bowl a strike in the tenth frame, you get two more balls. If you throw a spare, you get one more ball.

Scoring is based on the number of pins you knock down. However, if you bowl a spare, you get to add the pins in your next ball to that frame. For strikes, you get the next two balls.

• Line string has 10 (or 11) frames separated by a single space.
• Each frame has 2 (or 1) characters - one for each throw.
• The 1st can be a digit 0-9 or X to represent a strike.
• The 2nd can be a digit 0-9 or / to represent a spare.

• 02 00 00 00 00 30 00 00 00 07 (Score: 12)
• 20 00 X 1/ 03 04 00 00 00 70 (Score: 46)
• 20 00 X 1/ 03 04 00 00 00 0/ 1 (Score: 50)
• 12 4/ 20 X 35 X X 9/ 4/ X 81 (Score: 145)

Example implementation: https://www.sportcalculators.com/bowling-score-calculator (no need for this GUI).