In the world of computer science education, there are "trendy" resources that come and go with each programming language fad, and then there are bedrock texts—the books that build the foundational knowledge upon which entire careers are built.
Schaum’s Outline of Data Structures with C or Schaum's Outline of Combinatorics (related) is available on: data structures by seymour lipschutz pdf github
Sorting and Searching: Everything from Bubble Sort to Quicksort and Binary Search. Benefits of Using the Schaum’s Outline Series Unlocking the Classics: The Enduring Relevance of "Data
Buy the book – Still in print (Schaum’s Outline of Data Structures with Pascal, C, or C++ editions). Available new/used on Amazon, AbeBooks, etc. Benefits of Using the Schaum’s Outline Series Buy
However, the path of least resistance (random GitHub PDFs) is fraught with legal gray areas and security risks. The value of Lipschutz’s work is so high that it is worth acquiring legitimately—whether through a used bookstore, an official eBook, or a university library.