The book: https://www.crackingthecodinginterview.com/
This is for the 6th (latest as of now) edition of the book.
While I was preparing for landing an internship (3-4 years ago), one of the things I did was go through this book and solve the problems stated in it. It was a great way to learn your way around Algorithm & Data Structures for coding interviews. Even if the company you are interviewing with do not have Algorithms & Data Structures as part of the interviewing process, solving the problems in this book is great problem solving practice. You can also solve the problems just for the fun of it.
Correct solutions to problems are included in the Book and written in Java.
For each chapter the solutions are placed in separate files named "Chapter N: chapter_name". Also all problem solutions are included in the "All Problems" file.
Before every solution there is a problem number and the name of the problem as stated in the book (commented out).