The three books I clicked through several chapters of were unpleasantly focused on the features of the C# standard library and details of network administration

The three books I clicked through several chapters of were unpleasantly focused on the features of the C# standard library and details of network administration in Digital Ocean (?!?). Tim Roughgarten of Stanford has split his big algorithms book into four $20 paperbacks, so you can pick and choose an area you'd like to reinforce your knowledge of for not too much money.