A Common-Sense Guide to Data Structures and Algorithms, Second Edition, 2nd Edition

Chapter 11

These are the solutions to the exercises found in the section, ​Exercises​. The solutions provided here are in Ruby, but you can find the solutions in JavaScript and Python in the code download.^[11]

1. Let’s call our function character_count. The first step is to pretend that the character_count function has already been implemented.

   Next, we need to identify the subproblem. If our problem is the array, ["ab", "c", "def", "ghij"], then our subproblem can be the same array missing one string. Let’s specifically say that our subproblem is the array minus the first string, which would be ["c", "def", "ghij"].

   Now, let’s see what happens when we apply the “already implemented” function on the subproblem. If we were to call character_count(["c", ...