Chapter 6, Problem 17PE

Program Plan Intro

Program plan:

BarChartWithPositiveNegative.java

• Create a class named “BarChartWithPositiveNegative”.
  • Define a function named “readinputValues”.
    • Create an ArrayList object called “listofarr”, which will store integer values.
    • Using “while(in.hasNextInt())” loop, read all input values and add elements to the array list using “add()” method .
    • Return “listofarr”.
  • Define an “int” function named “findMaxElement”.
    • Declare an integer variable named “maxval” and access the list using “get()” method.
    • Using enhanced “for” loop, iterate and find the maximum value in the array list.
      • Inside the loop, the conditional statement “if” checks whether “a” is greater than “maxval” or not  
        • If the condition is true, the maximum value will be stored in the variable “maxval”
      • Return “maxval”.
  • Define an “int” function named “findMinElement”.
    • Declare an integer variable named “minval” and access the list using “get()” method.
    • Using enhanced “for” loop, iterate and find the maximum value in the array list.
      • Inside the loop, the conditional statement “if” checks whether “b” is greater than “minval” or not 
        • If the condition is true, the maximum value will be stored in the variable “minval”
      • Return “minval”.
• Define a function named “printBarChartforposneg”.
  • Declare an integer variable named “maximum” and call the function “findMaxElement”.
  • Declare an integer variable named “minimum” and call the function “findMinElement”.
  • Initialize “posAsterisk” as “40”.
  • Initialize “negAsterisk” as “0”.
  • Using “if” conditional statement, check whether the “Math.abs(minimum)” is greater than “maximum” or not.
    • If the condition is true, assign the value “40” into variable “negAsterisk” and then compute positive asterisks and store into the variable “posAsterisk”.
  • Else if check whether the minimum value is less than “0” or not and then compute negative asterisk and store into variable “negAsterisk”.
  • Using “for” loop, print and generate the bar chart.
    • Inside the “for” loop, using “get()” method retrieve a number from the values and store into the variable “num”.
    • Using the “if” conditional statement, check whether the “num” is greater than “0” or not.
      • If the condition is true, compute the number of asterisks and store into the variable “asterisks”.
      • Using “for” loop, print empty spaces for negative asterisks on the screen.
      • Using “for” loop, print asterisks on the screen.
    • Else, it computes the number of asterisk and stores it into the variable “asterisks”.
  • Using “for” loop, print spaces for the negative asterisks.
    • Using “for” loop, print asterisks on the screen.
• Define a main function.
  • Declare an array list variable named “Arrlist” and call the function “readinputvalues” to read a sequence of positive and negative values.
  • Call the function "printBarChartforposneg" and pass “Arrlist” as parameter for displaying the bar chart of asterisks based on the input list and maximum and minimum values in the array list.