ITEC 120 2010fall ibarland

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hw09
arrays
histograms (due Nov.19 (Fri) 17:00)

Complete the following exercises from the textbook. Submit just one program file; include the answers to the written problems as a comment at the start of your program.

• (5pts) Exercise 7.1
• (3pts) Exercise 7.3
• Exercise 7.4Deferred to a future homework.
• (32pts) Programming Project 7.4.
  (Your development will presumably pass through the stages of projects 7.1 and 7.3.
  When upgrading from 7.3 to 7.4, you might find it helpful to use input-redirection read input from a file, which we'll talk about in lab on Thursday.)
  Unlike the Listing 7.3, your program must include at least three methods:
  • A main driver which allocates and initializes the array, then calls the two methods below.
  • one method which reads numbers from System.in and tabulates the results:
  • A method which prints the histogram for a given array.
  You'll need to think closely about how your program will work, and what appropriate named constants you might use. In particular, when transitioning from state 7.1 to 7.3, you'll have a decision to make make about your data representation (good ol' step 1 of the design recipe).
  As always -- work incrementally: start with small/stub methods, and then gradually add more functionality.

  Write this program without using BlueJ -- just use a text editor and compile/run your program using the commands javac and java.

  You do not need to handle bad-input entered by the user (e.g. if they type in 101, it's okay for your program is allowed to crash). 3pts extra credit if your program never crashes on any input.

  As long as the output looks similar to what is suggested, it's okay. In particular, the row-headers can be slightly different lengths, due to "1 - 10" being one character shorter than "11 - 20". 3pts extra credit if you make them align.

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©2010, Ian Barland, Radford University Last modified 2010.Nov.30 (Tue)

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