"complexity analysis" ... "stuff you would learn in a computer science degree". Does she want theory? Does she want Software Engineering skills? Does she want

"complexity analysis" ... "stuff you would learn in a computer science degree". Does she want theory? Does she want Software Engineering skills? Does she want to be able to get a job? Cracking the Code Interview might be a fine jumping off point. It covers a lot of topics at a very readable level. If she doesn't understand it from the books angle, then she can do research on her own until she gets there. It covers stuff like "complexity analysis" in-depth enough for most people.