Probably some paper some computer.

Everything in the first test...

https://docs.google.com/document/d/1Epol0MmM4pgbLcvsQTGEs9rSXLEUQXyqJGT_MZINo9U/edit#heading=h.htxsdl4ifl2p

Memorize program candidates...
1. program that has an array of character arrays
   #define HOW_MANY 100000
   char words[HOW_MANY][100]; 
   And the program asks the users for a word, puts it into the array if it's not there
   already. ... unsorted array
   pseudocode...
   while (they didn't type quit) {
     ask them for a word.
     check if the word is already in the array.
     if not, add it to the array.
   }
   print all the words.
   

Math/memorize stuff.
... log(1024) = log(2^10) = 10*log(2) = 1
... (3^3)^5 = 3^15
... (1+2+3+...+1000) = 
... (1 + 1/10 + 1/100 + 1/1000 + ... 1/(10^10))
... also bits, bytes, GB, ..., max/min sizes of int, char, short, long


Everything that can be done in C
* structures - make a new struct and use it.
  (1) Define a new structure that has doubles for hw grade, exam grade, project grade.
      Declare a variable of that type and set the values.
* pointers - make a function that returns more than one value, by using pointer parameters.
  E.g., function that takes an array of doubles and returns max, min, and average
* be awesome with arrays...
* printf, scanf, strlen, sprintf, exit, fopen, fgetc (fscanf), fclose

Algorithms/data structures - fill in a little of missing code, and also answer "thinking" questions
* unsorted arrays - keep track of how many used so far,
  - insert - put it on the end, and increase how many used so far
  - lookup - for loop
* sorted arrays
  - insert - find where it should go, shift everything else down
  - lookup - binary search
* hash tables
  - array to store things in
  - everything you want to store has some data and also a "key"
  - key is what you do a lookup with, data is all the data
  - "hash" the key - some random-ish thing that converts the key into a valid
    index into your array.
  - wherever the key hashes, that's where store that item.
  - problem: collisions - two different keys that hash top the same array index.
  - what to do about collisions: if something else is where you're supposed to be, then
    try the next index.

Running time in the worst case, say n is how many things we have
                insert	    lookup
unsorted array	1	    n
sorted array	log(n)+n    log(n)
hash table	n	    n

Running time on average
                insert		  lookup
unsorted array	1	    	  n/2
sorted array	log(n)+n/2   	  log(n)
hash table*	O(1)	    	  O(1)
* if things are good and there aren't too many collisions