Computer Science

if x = [4,7,9,2] what is x[2]

9

indicate the data type of the expression: 5/2 == 5/2.0

Boolean

the person who popularized the term "debugging" was

Hopper

What is the run-time complexity of the following program? def findTarget(myList, target): count = 0 for item in myList: if (target == item): count = count + 1 return count

O(n)

range(0,n) creates a list of

[0,1,2,.....,n-1]

library

a collection of useful algorithms

if python 2.7, if x = 13 and y = 2, what is x/y a. 6 b.6.0 c.6.5 d. 7

a. 6

if x = 5.0 and y = 3, what is the data type of x*y a. integer b. float c. string d. list

b. float

fundamental building blocks of all computer systems

binary representation boolean logic gates circuits

A program in python prompts the user for input from the keyboard and will store the value as the variable myAnswer. The user types the value 3.0. At this point, the data type for myAnswer is:

string

a word with quotes

string

indicate the data type of the expression: str(2.6)

string

x = "3" what is type(x)?

string

string

the " " that enclose a phrase tell python its a string and treated as a single monolithic thing

in computer science terminology, the machine, robot person, or thing carrying out the steps of an algorithm is called

the computing agent

computer science

the study of algorithms, including their formal and mathematical properties their hardware realizations their linguistic realizations their applications

misconceptions: computer science is...

the study of computers the study of how to write computer programs the study of building/designing new machines

"doable"

there exists a computational process that allows the computing agent to complete the operation successfully. Formal term is effectively computable

period of the wave (T)

time it takes for the wave to make 1 complete cycle units: time(sec)

frequency f

total # of cycles per unit of time units: Hertz (Hz)

two's complement representation

total number of values that can be represented with n bits is 2^n

abstraction

use of high level instructions during the design process separation from the high level view of an entity or operation from the low level details of its implementation

virtual machine/environment

user oriented view of computer system

UNICODE

uses 16 bit representation for characters rather than the 8 bit rep of ASC II

digital representation

values for a given object are drawn from a finite set

a word without quotes

variable

top down design

viewing an operation at a high level abstraction

algorithm(formal)

well ordered collection of unambiguous and effectively computable operations that, when executed, produces a result and halts in a finite amount of time

primitive operation

when an operation is unambiguous (understood and carried out directly by the computing agent w/o further simplification or explanation)

3.3//2

1

if python 3.4, if x = 13 and y = 2, what is x/y a.6 b.6.0 c.6.5 d.7

c. 6.5

which of the following data types is mutable? a.float b.integer c.string d.list

d.list

read

evaluate-print cycle- infinite times

Given the following script in python, what will be printed? N = 0 if (N > 0): print("you entered a positive number") else: print("you are not feeling very positive") if (N == 0): print("you entered zero")

you are not feeling very positive you entered zero

Given the following program in python, what will be the value returned? N = 3 counter = 0 while (N > 0): counter = counter * N N = N - 1 return counter

0

Given the following script in python, What will be value of N when the program terminates? N = 4 counter = 1 while (N > 0): counter = counter * N N = N - 1 return counter

0

Rules

1. Direct Sequencing 2. Conditional Execution 3. Iterative Execution

3.3/2

1.65

sequential operations (3)

1.computation- evaluates the arithmetic expression, gets a result, and stores that result in the variable 2. input- provide computing agent with data values from the outside world 3. output- send results from computing agent to outside world

max number of binary digits that can be used to store an integer

16,32,64 bits

ENIAC

1st fully electronic general purpose programmable computer

FORTRAN and COBOL

1st high level programming languages

round(5/2)

2

def myFunction(a,b): return 2 * b + a what is myFunction(3, 10)?

23

What will be the value returned from this script? N = 4 counter = 1 while (N > 0): counter = counter * N N = N - 1 return counter

24

what is the final value of y when the following statements are entered in python? >>>x = 3 >>>y = x + 1 >>>x = 7

4

x =4 y= x x=7 what is y?

4

computer science is the study of

algorithms

a while statement is an example of

an iterative statement (looping instruction that doesn't say to go on but to go back and repeat)

iterative execution

applies to an iterative construct(loop, for, while) that will cause the execution of a subset of instructions to be repeated a specified number of times the trick is to understand how many times the instructions will be repeated

code mapping

assigning each printable letter or symbol in our alphabet to a unique number

Which of the following data types is mutable? a. integer b. float c. list d. string

c. list

which of the following statements describes the primitives of a computing agent? a. They are variables that can only store numerical values. b. They are written in pseudocode and form a basic outline of an algorithm. c.They are instructions that the computing agent understands and can execute without further explanation or simplification. d. They evaluate "true/false conditions" to determine if a loop body should be executed.

c. they are instructions that the computing agent understands and can execute without further explanation or simplification

control operations

conditional and iterative allow us to alter the normal flow of control in an algorithm

the question asking operations of an algorithm are called

conditional statements

Big O

constant run time O(1) logarithmic run time O(log n) linear run time O(n) linearithmic run time O(n log n ) quadratic run time O(n^2)

Gottfried Leibinitz

constructed a mechanical calculator called Lebnitz's Wheel. Also developed formal logic using binary system (-,+,*,/)

posttest loop

continuation condition at the end of each loop body

pretest loop

continuation condition tested at beginning of each loop

The list of numbers [6, 2, 3, 1, 5, 4] is to be sorted using BUBBLE SORT. The algorithm for this process involves nested "for" loops. Which of the following lists is an intermediate result after the first pass over the outer loop has been completed? a.[2, 6, 3, 1, 5, 4] b.[1, 2, 3, 6, 5, 4] c.[1, 2, 3, 4, 5, 6] d.[2, 3, 1, 5, 4, 6]

d. [2,3,1,5,4,6]

which of the following is NOT part of the formal definition of an algorithm? a. it produces a result b. it halts in a finite amount of time c. it consists of unambiguous operations d. it consists of step-by-step instructions

d. it consists of step by step instructions

Which of the following has the most optimal worst-case run-time complexity (in terms of the lowest order)? In other words, which of the following sorting algorithms is the most efficient (in the worst case)? a.bubble sort b.insertion sort c.selection sort d.they all have the same run-time complexity

d. they all have the same run-time complexity

Which of the following statements is CORRECT regarding Leibnitz's Wheel and the Pascaline a. They were programmable b. They are examples of early computers c. They had memory where information could be stored d. They were mechanical calculators

d. they were mechanical calculators

Blaise Pascal

designed and built one of the first mechanical calculators (named the Pascaline) (-,+)

Grace Hopper

developed first complier for a compare programming language credited with "debugging" for fixing computer glitches United States Navy seal admiral annual conference celebrating women in CS

string * non integer string * integer

error "hello" * 5 = hellohellohellohellohello

John von Neumann

father of computer virology designed a self reproducing computer program (virus) member of Manhattan Project produced different program design called stored program computer invented programming invented "merge sort"

Herman Hollerith

father of the modern automatic computation founded the Computer Tabulating Recording Company 1940- his tabulating machine company changed to IBM

Alan Turing

father of theoretical computer science wrote chess program defined standard for a machine to be called "intelligent"

algorithm discovery

finding a solution to a given problem

indicate the data type of the expression: 5/2

float

indicate the data type of the expression: 3 + 5.0

float

integer + float string + string string + integer string + float integer + integer float + float

float string error error integer float

conditional execution

for a conditional statement, the cost of execution is the maximum cost of evaluating the condition and the cost(s) of the alternate instruction sequences

direct sequencing

for a sequence of instructions, the cost of executing the sequence of instructions is, asymptotically speaking, the same as the maximum cost of the individual instructions

pass

give or pass info by enclosing it in parenthesis

primitives

instructions that computing agent understands

ASC II

internal standard for representing textual info in the majority of computers uses 8 bits to represent each character

John Napier

invented logarithms to simplify difficult math problems

4 data types

lists strings integers floats

Jacquard

made automative weaving process 1st programmable device

python interpreter

magic that underlies the evaluation part of shell. Responsible for translating commands you type into instructions

sampling rate

measure how many times per second we sample the amplitude of the sound wave

amplitude of the wave

measure of its loudness units: electrical voltage

variable

named storage location that holds data value

issues with using natural language to represent algorithms

natural language can be extremely verbose lack of structure makes it difficult to locate specific sections of the algorithm too rich in interpretation and meaning

pseuedocode

natural language:used to express algorithms, not sufficiently precise to represent algorithms used to design and represent algorithms a compromise between the two extremes of natural and formal language not unique

analog representation

objects can take on any value

sign/magnitude notation

one of a number of different techniques for representing positive and negative whole numbers 1- negative 0- positive

Charles Babbage

one of the "fathers of the computer" designed the Difference Engine (+,-<*,/ to 6 digits, solve polynomial equations), never completed designed the analytic engine, similar to modern computer, never actually built (mill,store, operator, output, input)

arithmetic overflow

operation that produces an unsigned value greater than 65,535

pattern matching

process of searching for a special pattern of symbols with a large collection of information

Ada Byron

regarded as history's 1st computer programmer Ada programming Her notes include what is recognized as first algorithm intended to be carried out by a machine

loop

repetition of a block of instructions while statement

infinite loop

runs forever

program/script

sequence of python instructions

operations used to construct algorithms

sequential conditional iterative

sequential algorithm

sometimes called straight line algorithm

sequential search

start at beginning and look at each one, one at a time, used for unordered lists

algorithm(unformal)

step by step instruction to accomplishing a task