Last month I borrowed a plenty of books from the library. They all were good books, packed with emotions and plot-twists. Unfortunately, at some points I got very angry/sad/disappointed, so I tore some pages out.
Now the library wants to know how many pages I have torn out for each book.
Your goal is to write a program, which takes a sorted, comma-delimited list of numbers as input and prints the minimum and maximum possible page count I could have torn out. Each line represents a book, each number represents a missing page from the book.
7,8,100,101,222,223 2,3,88,89,90,103,177 2,3,6,7,10,11 1 1,2
4/5 5/6 3/6 1/1 1/2
4/5 means, that I may have torn out either 4 or 5 pages, depending on which side the book's page numbering starts. One could have torn out page 6/7, page 8/9, page 100/101, and page 222/223 (4 pages). Alternatively, one could have torn out page 7/8, page 99/100, page 101/102, page 221/222, and page 223/224 (5 pages).
Remember that a book page always has a front and a back side. Also the page numbering differs from book to book. Some books have even page numbers on the left page; some on the right page. All books are read from left to right.
Shortest code in bytes win. Strict I/O format is not required. Your programs must be able to take one or more books as input. Have fun.