Jack WattsFantastic Guide for Fake CompSci Knowledge

Jack Watts
’s
Fantastic
Guide for Fake CompSci Knowledge

Data Structures:

Tree
:


-
Varieties:
Red
-
black
, B version, AVL, self
-
balancing, Minimum Spanning


-
zig, zig
-
zig, and zig
-
zag steps


-

Prim +Kruskal algorithm
-

used in the
minimum spanning

kind


-
traversing them
-

can be done in
Preorder, Inorder, Post
-
Order


-
Heaps
-

when the child values are always LESS than the parent values


-
Suffix

and
prefix


-
acyclic connected graphs


-
root and leaf nodes

Stack
:


-
Reverse Polish Notation


-
push and pop
= in and

out operations


-
last in, first out


-
commonly use divide and conquer algorithms


-
In C++, “this” is a pointer in a stack (not a common clue but may be worth knowing)

Arrays
:


-
Constant lookup time, unlike linked lists


-
denoted by
square brackets


-
multi
-
dimensional types
-

useful for storing matrices

Linked Lists
:


-
CAR and CDR

coding


-
sentinel nodes


-
basic data structure in
LISP


-
types: single, double, linear, circular


-
Each node has 2 fields
-

its value and location of the next value

Algorithms (note
: specific versions of algorithms are tossed up sometimes, be careful):

Search
:


-
Grover’s algorithm
-
can accomplish it in √n time and log
2
n space in quantum computing


-
on graphs
-
can be
best
-
first, breadth
-
first, depth
-
first

-
Binary

form
-

assumes list is sorted and eliminates ½ on each pass by picking the middle
element
-

improvement of NAÏVE methods


-
can be done in constant time in a well
-
built hash table


-
genetic algorithms optimize it


-
reads elements and compares to target (key
word)

Sort
:


-
types:
merge
, binary tree,
bubble
,
Bozo

(like the clown),
quick
, heap

-
bubble sort
-

I have no idea what the technical process is, but it essentially moves s
tuff

around
until it’s good
-

listen for the description
, it’s named because the result
s “float” to the top


-
quicksort
-

invented by
C.A.R Hoare
-

uses pivot values

Misc
:

Pointers
:


-
during
(de)serialization

they can undergo
(un)swizzling


-
Wild and dangling

ones
-

can lead to segmentation faults


-
In C and C++ they are denoted by an asterisk


-
Each node in a linked list has 2 of them


-
smart type=automatic garbage collection


-
iterators
-

a type subject to postfix operators

-
what they are: references that hold memory addresses of things, not the actual data of the
things


Compilers:

-
Dragon Boo
k=a tome describing their designs (I’ve only heard this clue once, but it sounds cool
so I’m including it)

-
Yacc
-

pronounced like yak, stands for Yet Not Another Compiler Compiler

-
Javac

(Java
-
see)
-

Java compiler

-
tokenization

and syntax
,type
-
checking

-
constant folding and loop unrolling

-
source
-
to
-
source

-
bootstrapping
-

writing one in its own source language

-
What it is
-

essentially a translator from one language to another