EECS 281 discussion 1 notes

gistfile1.md

C++ I/O

• cin.get

• cin.unget

• getline(cin, var)

• cin >> var

• cout is slow because it has to go to the operating system

• To have good speed, use internal buffers. Use ostringstream to build it up, build it up, and then when you're done, finally do only one cout: cout << myStringStream.str()

getopt

• Helps you deal with command line arguments and options.

• Arguments versus options: ls -a has -a as an argument, cd hi has hi as an argument

• Passing argc and argv to getopt to the function, it helps you

• getopt has a website and the slides have stuff too

• getopt_long you can have things like --help; words, rather than just single-character ones

Complexity

• O(g(n)) = f(n) if g(n) is an upper bound to f(n)

• Big omega means the worst case

• Big theta means that the upper bound and lower bound are the same thing

• 2x^4 + 2x = O(x^4)