Basics

Question 1

define Algorithm

Answer 1

a step-by-step list of instructions for solving any instance of the problem that might arise

Question 2

what does the word computable mean

Answer 2

A problem is computable if an algorithm exist for solving it

Question 3

define Abstraction

Answer 3

Allows one to take a problem and separate them into logical processes

Question 4

define Interface

Answer 4

functions that allow the user to interact with the system

Question 5

Programming

Answer 5

is the process of taking algorithm and encoding it into a notation, a programming language, so that it can be executed by a computer. Without an algorithm there can be no program

Question 6

Data Types

Answer 6

Data Types provide an interpretation for binary data so that we can think about the data in terms that make sense with respect to the problem being solved. Low level or primiative data types provide the building blocks for algorithm development

Question 7

Abstract data type

Answer 7

a logical description of how the user views the data in that they are concerned with the allowed operations and used (its behaviour) of the data without regard to how the will to the implementation.

The Abstract data type is the shell the user interacts with. The implementation is hidden one level deeper

Question 8

Data Structure

Answer 8

A data structure is a collection of data values, the relationships among them, and the functions or operations that can be applied to the data. The implementation of an abstract data type

Question 9

Class

Answer 9

A class is a code template for creating objects. They are analogous to data types in that the user of a class only sees the state and behavior of a data item.

Functionalities of a class are defined by setting attributes, which acts as containers for data and methods (aka functions) related to those attributes.

Objects are created or instantiated from a class or done so through a subroutine called a constructor

Classes are a description of what the data looks like (the state) and what the data can do (the behavior)

Question 10

List (Python)

Answer 10

A list is an ordered collection of zero or more references to Python data objects. They are heterogeneous meaning that there members do not need to belong to the same class.

Lists are mutable, meaning they can be modified.

in Python a list is given by var = [obj1, obj2, …]

Question 11

range (Python)

Answer 11

A function that produces a range object that represents a sequence of characters.

Question 12

Strings (Python)

Answer 12

Strings are sequential collections of zero of more letters, numbers and other symbols.

Strings are immutable, meaning they cannot be modified

Question 13

Tuples (Python)

Answer 13

Very similar to list in that the are heterogeneous sequences of data. The differences is that a tuple is immutable, like a string.

However, because they are immutable, Python allocates larger blocks of memory with lower overhead. This means Tuples can be faster to work with as compared to Lists

in Python a tuple is given by var = (obj1, obj2, …)

Question 14

set( ) (Python)

Answer 14

A set is an unordered collection of zero or more immutable Python data objects. The empty set is represented by “set( )”. Sets are heterogeneous, and the collection ca be assigned to a variable as below

in Python a set is given by var = {obj1, obj2, …}

Question 15

dictionary (Python data structure)

Answer 15

A dictionary is an unordered structure that contains a key-value pair are are typically written as key:value.

Ex: phone_ext = {‘david’ : 1137, ‘brad’ : 1212, … : …}

Question 16

control structures

Answer 16

think of iteration and selection. These options allow the programmer to choose the statement that is the most useful for the given circumstance.

Examples include “while” and “for” statements

Question 17

list comprehension

Answer 17

a list comprehension allows one to create a list based on some processing or selection criteria.

Question 18

shallow equality

Answer 18

if the two variables reference the same object.

Question 19

deep equality

Answer 19

if two variables reference different objects but both have the same value

Question 20

Define the term Loop Invariant for a set or array of values.

Answer 20

The values of an array do not in a loop although their indices may change. We need to show three things:

1) it is true prior to the first iteration
2) it remains true before the next iteration
3) when the loop terminates, the invariant gives us a useful property to show the algorithm is correct