unit 3

Question 1

what is an array

Answer 1

list within a code
fixed in size and need declaring before use

Question 2

what is a 1d array

Answer 2

most basic array
single index to reference
use a single access method

Question 3

what is a 2d array

Answer 3

grid of rows and columns
data is accessed using a row and column indicator

Question 4

what is a 3d array

Answer 4

cube like structure of 2d arrays
layers rows and columns

Question 5

what is a stack

Answer 5

data structure capable of holding a linear sequence of items
last in first out
one item is pushed in and first item is popped

Question 6

what is a push operation

Answer 6

adds a new item to stack
each item added adjusted the top pointer position

Question 7

what is a pop operation

Answer 7

removes an item
only adjusts the top pointer may not remove data

Question 8

what is a linked list

Answer 8

dynamic data structure
head and tail pointers
can be ordered or unordered
when removing gives a previous node the deleted nodes pointer

Question 9

what is a queue

Answer 9

holds linear sequence of items
first in first out

Question 10

what does enqueue do

Answer 10

adds an item to the queue

Question 11

what does dequeue do

Answer 11

removes the oldest item in the queue

Question 12

what is a binary tree

Answer 12

root node connected to child nodes/parent nodes

Question 13

what are the uses of a binary tree

Answer 13

storing ands managing files
path finding algorithms
records data by heirarchy

Question 14

what is data

Answer 14

what’s being stored

Question 15

what is a left pointer

Answer 15

location of left child node

Question 16

what is a right child node

Answer 16

location of right child node

Question 17

what is pre order traversal

Answer 17

node left right
start at root, follow left node down then follow right edge

Question 18

what is in order traversal

Answer 18

left node right
start at left node, then to root then to right node

Question 19

what is post order traversal

Answer 19

left right node
start at root, go left, go right

Question 20

what is a hash table

Answer 20

makes use of array
generates an index number from the data
fast access

Question 21

what is the load factor

Answer 21

n/k
occupied/total number

Question 22

what is a hash function

Answer 22

hash value from a key then undergoes a MOD calculation

Question 23

what are collisions

Answer 23

data gets overwritten when the hash functions produce the same hash values for two or more keys

Question 24

what is linear probing

Answer 24

stores the value in the next available space when collision occurs
very slow

Question 25

what is chaining

Answer 25

data stored with pointer value, pointer changes after a collision to show new location much faster