gcse computer science paper 2

paper 2 computational thinking

Ask user for an integer input

int(input()

When would you use a while loop?

When it is not known how many times iteration will occur.

while loop which will add 1 onto 0 until it reaches 8

number = 0 
while number != 8:
 number = number + 1 
 print ("The number is",number)

while loop

condition controlled

for loop

count controlled

count controlled meaning

you specify the number of times that you wish the iteration to be repeated

for loop, repeat 10 times until it reaches 5

for i in range(10):
 if i == 5:
  break
print(i)

MOD definition (%)

calculates the remainder of a division

iteration

The repetition of a block of statements within a computer program.

selection

the process of making a decision which result will decide which path it takes next

sequence

a set of instructions that follow on one from another

nesting

one programming construct within another

start/end

process

input/output

if

flow

Abstraction

Removing the unnecessary parts of a problem so that you only focus on the important parts

Decomposition

Breaking a complex problem down into smaller problems so that it is more manageable/easier to solve

Binary Search

A type of searching algorithm. In order to use a binary search the data set must be in order.

Linear Search

A type of searching algorithm. The data set does not need to be in order when using a linear search.

Sorting Algorithm

A type of algorithm used to sort a data set into a specific order

Bubble Sort

A type of algorithm used to sort a data set into a specific order. The data set is passed through, and two pieces of data are looked at in turn. The process does not stop until a pass is completed without moving any data.

Merge Sort

A type of algorithm used to sort a data set into a specific order. The data set it broken up into pairs. Each pair is reorganised in turn. Pairs are then merged together and reorganised. This process is repeated until the whole data set is merged and reorganised

Insertion Sort

A type of algorithm used to sort a data set into a specific order. A new, temporary list is created, and each piece of data is placed into the correct place in the new list.

Trace Table

Used to test an algorithm for logic errors by simulating the flow of execution.