Books like Purely Functional Data Structures
Chris Okasaki
Purely Functional Data Structures is 220 pages, about 4 hours 2 minutes at 250 words a minute.
7 books to read next
How long each takes
Data Science from Scratch 6.1 h 
Schaum's Outline of Theory and Problems of Data Structures 6.3 h 
Data Structures and Algorithms 7.8 h 
C++ Programming 27.5 h 
An Introduction to Computer Science 13.2 h 
Data and Reality 3.9 h 
Data Structures 9.4 h Bar height shows length. Estimated at 250 words a minute.