Year 10 - Paper 2

Question 1

Binary search

Answer 1

Has to have items in order. It finds the middle number, and compares it to the answer. If the middle is lower than the item, the first half of the list is removed. Repeated until found

Question 2

Sorting

Answer 2

When we arrange the list in a certain order

Question 3

Bubble sort

Answer 3

Compares two items in a list, swaps them if needed, this needs to go through the list multiple times.

Question 4

Insertion sort

Answer 4

Puts items in correct place, based on already sorted items.

Question 5

What’s abstraction?

Answer 5

Removing unnecessary detail and focusing on the important parts, this helps to simplify the problem

Question 6

What’s Decomposition?

Answer 6

Breaking a problem into a smaller problem, which makes it easier to solve

Question 7

What’s Algorithmic thinking?

Answer 7

The process of turning the solution of the problem into a set of clear instructions

Question 8

What are inputs?

Answer 8

Clear pieces of data we need to give the code

Question 9

What are processes?

Answer 9

What the computer does with this data

Question 10

What are outputs?

Answer 10

What the computer returns to the user

Question 11

What are structure diagrams?

Answer 11

A graphical way of representing a problem, showing the different levels of detail. They often show the functions of a program with the sub-functions branching below them.

Question 12

What’s a logic error?

Answer 12

Does not prevent the program running, but it does not produce the expected output

Question 13

What’s a syntax error?

Answer 13

An error that breaks the rules of the programming language, it will not run the program

Question 14

What are trace tables?

Answer 14

When we go through the code and record what values the variables take. We can also find the output. This is a good way of looking for logic errors

Question 15

What’s searching?

Answer 15

When we look for a specific item in a list

Question 16

Binary search only works with…

Answer 16

sorted lists

Question 17

How does binary search work?

Answer 17

Finds the middle number, compares that to the answer. If the middle is lower than the item, the first half of the list is removed. This is repeated until the item is found

Question 18

How does a linear search work?

Answer 18

Checks each item in turn to see if it is the correct one, starting from the beginning

Question 19

How does bubble sort work?

Answer 19

Compared 2 items in a list, starting from the beginning, and swaps them if needed. It then moves onto the next pair

Question 20

How does Merge sort work?

Answer 20

The list is repeatedly divided into two until all elements are separated individually. Pairs of elements are ten compared, placed into order and combined. This is repeated until the list is recompiled as a whole

Question 21

How does insertion sort work?

Answer 21

Puts items in the correct place, based on already sorted items. If the value it is looking at is greater than the value to the left of it, no changes are made. Otherwise this value is repeatedly moved left until it meets a value that is less than it. The sort process then starts again with the next value. This continues until the end of the list is reached.

Question 22

What’s a variable?

Answer 22

A location in memory that stores data, this data can be changed while the program is running

Question 23

What is a constant?

Answer 23

A location in memory and the value that does not change (while the program is running)

Question 24

For loops are…

Answer 24

count controlled

Question 25

While loops are

Answer 25

condition controlled

Question 26

What is casting?

Answer 26

When we convert to a different data type (e.g srt(), int())

Question 27

String manipulations - concatenation

Answer 27

When two or more strings are joined together. There are no commas in concatenation

Question 28

Case sensitive

Answer 28

When a user inputs something in e.g. upper case when it should be lower case, and a logic error occurs. To change to uppercase, we add .upper() to the end of a print statement and .lower() for lowercase. For only the first letter to be in caps, we use .capitalize(). e.g. print(x.lower())

Question 29

Slicing

Answer 29

When we slice parts of a string. To extract the first x characters in a string, we use .left(x) / extract the last x characters in a string we use .right(x)

Question 30

read, open, write and close files

Answer 30

read = variable.read() / open = variable = open(“filename.txt”, “r”) / write = variable.write(field1 +field2 + “\n”) / close = variable.close()

Question 31

What’s a local variable

Answer 31

Variables that only work in the subprogram and are not recognised by the rest of the main program

Question 32

What’s a global variable

Answer 32

recognised/available to the entire program, including subprograms

Question 33

Computational thinking

Answer 33

formulating a problem and expressing its solution in a way that a computer can carry out