Topic 4: Programming (Searching, Sorting and Psuedocode)

collecting input

input VARIABLE

collecting input with a prompt

VARIABLE = input(“prompt”)

displaying output

output VARIABLE 
output “text” 
output VARIABLE, “text”, VARIABLE

declaring variables (general)

VARIABLE = value

declaring multiple variables

VARIABLE1 = value1; VARIABLE2 = value2

declaring variables (boolean)

boolean VARIABLE = True or False

declaring variables (array)

VARIABLE ARRAY

Arithmetic Operators

A=3+3 = 6
B=3-3 = 0
C=3*3 = 9
D=3/3 = 1
E = 3 mod 3 = 0 //remainder
F = 3 div 3 = 1 //integer solution
G = abs(C-11) // Calculate the absolute valueB

Boolean Operators

>

<

>=

<=

!=

=

if-then-else

if condition then 
	//code 
else if condition then 
	//code 
else 
	//code 
endif

while loops

loop while condition 
	//code 
endloop 

for loops

loop counter from start to end 
	//code
endloop

create a queue

Q = new Queue()

Add to end of queue

Q.enqueue(VARIABLE) 	

remove from start of queue

VARIABLE = Q.dequeue()	

check if a queue is empty

Q.isEmpty()	

declare a new stack

S = new Stack()	

Add an element to the top of stack

S.push(VARIABLE) 	

Remove item from top of stack

S.pop()	

check if stack is empty

S.isEmpty()

Linear Search (sequential search)

Progresses from beginning to end of array and check whether each element is equal to the target value

Binary search

Can only be used on a sorted algorithm. The computer checks the middle term, sees if the target value is more or less than, and then proceeds to the corresponding half to repeat the process until the target value is found or the entire designated section has been searched through.

Bubble Sort

Goes through an array, comparing each pair of elements, and swaps the elements if they are out of order. The process repeats until the array is fully sorted and no more swaps are made.

Merge Sort

A sorted and unsorted array are made. The values in the unsorted array are picked out and added to the sorted array in the order that they need to go.