COSC 1306 COMPUTER LITERACY FOR SCIENCE MAJORS Jehan-François Pâris jfparis@sbcglobal.net

Download COSC 1306 COMPUTER LITERACY FOR SCIENCE MAJORS Jehan-François Pâris jfparis@sbcglobal.net

Post on 11-Jan-2016

218 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • COSC 1306COMPUTER LITERACY FORSCIENCE MAJORSJehan-Franois Prisjfparis@sbcglobal.net

  • FIRST REVIEW SESSION

  • First QuestionWe saw in class that Pascals calculating machine was not a commercial success. Why does it remain important?

  • AnswerIt showed that adding/subtracting machines could be built:Proof of concept

  • Second QuestionImplement the Boolean function a and (b or c) using switches assuming that closed switches correspond to true values.

  • AnswerTip:When you see an and, put the switches in series (one after the other)When you see an or, put the switches in parallel

  • Answerabc

  • Third QuestionWhat characterizes a von Neumann computer?

  • AnswerA von Neumann computer has a memory in which it stores both its programs and its data

  • Fourth QuestionCan you find examples of (a) a time-sharing system that is not interactive and (b) an interactive system that is not a time-sharing system?

  • AnswerI do not have any great example

    Your PC: interactive but not shared

  • Fifth QuestionWhat is the most likely reason your computer takes so much time to boot?

  • AnswerIt has to bring too many things in main memoryThe kernelAll the other programs that are set to be loaded in main memory a boot timeOften junkware

  • Sixth QuestionYou are going to the University Center with a nerd who claims he has an algorithm for finding out what is the best available flavor at the ice cream shop. Can you guess his algorithm?

  • AnswerGetting samples of all flavors being offered that day before making a decision

  • Seventh QuestionDescribe a practical heuristic for the same problemWhy is it a heuristic?

  • AnswerThinking of your favorite flavors and maybe asking for a sample of an interesting flavor

    You are very likely to get a flavor you will like but could have missed an even better tasting flavor

  • Eighth QuestionYou have to search for an item in a list of 20 of them.Does it make a big difference if you use linear search or binary search?Would it be true for a list of 50,000 items?

  • AnswerNo, it would not make a big difference for a list of 20 itemsLinear search is the best solutionSimplerYes, it would make a big difference for a list of 50,000 itemsBinary search is the best solutionMuch faster (average of 16 steps vs. 25,000)

  • Ninth QuestionWhich of the following items are (a) constants, (b) reserved words (c) variables and (d) expressions?3.5 _________elif _________ while _______44 _________ input/output _____ side-car _________ False ________rhubarb _________ '27 _________indeed _________

  • AnswerWhich of the following items are (a) constants, (b) reserved words (c) variables and (d) expressions?3.5 __(a)_____elif ___(b)_____ while __(b)____44 ___(c)______ input/output _(d)_ side-car __(d)____ False __(a)_____rhubarb __(c)____ '27 ____(a)____indeed __(a)____

  • Tenth QuestionWhat is probably wrong with the following Python code?

    nfingers = input(How many fingers do you have?) if nfingers != 20 : print(Did you lose some in an accident?)

  • AnswerTwo thingsThe string in the second print statement is not properly terminatedWill be caught by interpreterWe compare a string value with an integer constantNot caught by interpreter

  • Eleventh QuestionWhat will the following Python program print?code = 5 if code == 1 print(Hello!) print(Goodbye!)

  • AnswerThe interpreter will catch the missing semicolon butcode = 5 if code == 1 : print(Hello!) print(Goodbye!)will print Goodbye!

  • Twelfth QuestionWrite a Python program prompting for two floating point numbers and computing their average

  • What we need to doPrompt for first number, read it and convert to floatPrompt for first number, read it and convert to floatCompute averageDisplay average with 3 decimals

  • Answer# average.py a = float(input("Enter first number: ")) b = float(input("Enter second number: ")) average = (a + b)/2 print(Average is %.3f" % average)

  • Thirteenth QuestionWhat are the values of the variables a, b, c, d after the following Python code is executed? a = 4 * 2 0.5 b = 2 c = a // b d = a == ca = _________b = _________ c = _________d = _________

  • Answera = 4 * 2 0.5 b = 2 c = a // b d = a == ca = ___7.5___b = ___2_____ c = ___3_____d = __False____

  • Fourteenth QuestionWhat is wrong with the following Python code?i = 1 while i > 0 : print(Going though the loop!) i = i + 1

  • AnswerThe programi = 1 while i > 0 : print(Going though the loop!) i = i + 1will never end as the variable i is incremented instead of being decremented

  • Fifteenth QuestionWhat is wrong with the following Python code?i = 5 while i > 0 : print(Going though the loop!) i = i - 1

  • AnswerThe programi = 5 while i > 0 : print(Going though the loop!) i = i - 1will never end as the variable i is not decremented inside the loop

    *

Recommended

View more >