Computer Science 1

1
Computer Science 1

• 10/16/06

2
Welcome Back

• What linear constructs do you recall?
• Decision constructs??
• Looping constructs???
• When would use these??
• Today
• Review repeat..until
• Dry run
• Fix it
• Work on program from last Tuesday ( Push)

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Dry run sample

• program dr10_16
• var
• a,b,cinteger
• begin
• b2
• a 10
• repeat
• c 3a - 10
• b b1
• writeln(a6, b6, c6)
• a a c div b
• until (agt25)
• writeln(a6, b6, c6)
• end

Write the variable names and how they change and
what shows on the screen.
4
Fix the following

• \\west\transfer\Smith\ComputerScience1\fixpair.pa
  s
• program Pairs!
• This program will count how many rolls it
  takes to
• get a pair
• begin
• writeln('Time to roll for pairs')
• repeat
• random(6) 1
• random(6) 1
• if roll pair then
• writeln( pair)
• end Of the repeat
• writeln('It took roll ' rolls 'to get a
  pair')
• end

Open the file from the transfer folder and save
it on your c drive for testing.
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Program options

• Guessing game. Implement the guessing game, but
  also include showing how many guesses it took the
  user to guess the number. The computer picks a
  number (1-100) and you guess it. The computer
  needs to tell you if your guess is high or low.
  When you guess it correctly, the computer shows
  how many guesses it took. Push Write a program
  where the computer guesses the number you enter.
• Ulams conjecture If you take any positive
  integer greater than one. If it is even you
  divide it by two, if it is odd, you multiply it
  by 3 and add 1. When you continue this process,
  you will eventually get down to 1. Write a
  program to verify or disprove this conjecture.
• Bridge Walker A person is in the middle of an 8
  bridge. They are equally likely to take a 1
  step to the right as they are to take a 1 step
  to the left. Write a program that will model
  this person walking back and forth on the bridge
  until they fall off. Then tell which side of the
  bridge they fell from and how many total steps it
  took.
• Yahtzee Model rolling five dice until you get a
  Yahtzee, count how many turns it took to get
  Yahtzee on the first roll. (All five dice
  matching)