Instructions

You're an avid bird watcher who keeps track of how many birds have visited your garden in the last seven days.

You have six tasks, all dealing with the numbers of birds that visited your garden.

1. Check how many birds visited today

Implement the today() function to return how many birds visited your garden today. The bird counts are ordered by day, with the first element being the count of the oldest day, and the last element being today's count.

2. Increment today's count

Implement the increment_todays_count() function to increment today's count:

3. Check if there was a day with no visiting birds

Implement the has_day_without_birds() function that returns true if there was a day at which zero birds visited the garden; otherwise, return false:

4. Calculate the number of visiting birds for the first number of days

Implement the count_for_first_days() function that returns the number of birds that have visited your garden from the start of the week, but limit the count to the specified number of days from the start of the week.

5. Calculate the number of busy days

Some days are busier that others. A busy day is one where five or more birds have visited your garden. Implement the busy_days() function to return the number of busy days:

6. Calculate averages by day of the week

You decide to extend your records by keeping counts for multiple weeks. In each case, the counts are arranged by day of the week, from Monday as the first entry to Sunday as the last.

Implement the average_per_day() function that returns the average for 2 weeks.