Programming Assignment 4

Due: Wed. Sep. 27 before lab

1. (25 points) Problem 5.1 of the book. Count positive and negative numbers and compute the average of numbers. Write a program that reads an unspecified number of integers, determines how many positive and negative values have been read, and computes the total and average of the input values (not counting zeros). Your program ends with the input 0. Display the average as a floating-point number.
   • Name the file and program ch5pr1.java.
   • Example execution (java ch5pr1) user provides input:
     
     Enter an integer, the input ends if it is 0: 1 2 -1 3 0
     The number of positives is 3
     The number of negatives is 1
     The total is 5
     The average is 1.25
   • Example execution (java ch5pr1) user provides input:
     
     Enter an integer, the input ends if it is 0: 0
     No numbers are entered except 0
2. (25 points) Problem 5.25 of the book. Compute π. You can approximate π using the following series:
   π = 4(1 - 1/3 + 1/5 - 1/7 + 1/9 - 1/11 + … + (-1)i+1/(2i - 1))
   Write a program that displays π value for i = 10000, 20000, …, 100000. Use System.out.printf for proper formatting.
   • Name the file and program ch5pr25.java.
   • Example execution (java ch5pr25):
     
        10000  3.141492654
        20000  3.141542654
        30000  3.141559320
        40000  3.141567654
        50000  3.141572654
        60000  3.141575987
        70000  3.141578368
        80000  3.141580154
        90000  3.141581542
       100000  3.141582654
3. (25 points) Problem 5.31 of the book. Financial application: compute CD value. Suppose you put $10,000 into a CD with an annual percentage yield of 5.75%. After one month, the CD is worth
   10000 + 10000 * 5.75 / 1200 = 10047.92
   After two months, the CD is worth
   10047.91 + 10047.91 * 5.75 / 1200 = 10096.06
   After three months, the CD is worth
   10096.06 + 10096.06 * 5.75 / 1200 = 10144.44
   and so on.
   Write a program that prompts the user to enter an amount (e.g., 10000), the annual percentage yield (e.g., 5.75), and the number of months (e.g., 18) and displays a table as shown below. Use System.out.printf to format the money amounts properly.
   • Name the file and program ch5pr31.java.
   • Example execution (java ch5pr31) user provides input:
     
     Enter the initial deposit amount: 10000
     Enter annual percentage yield: 5.75
     Enter maturity period (number of months): 18
     
     Month  CD Value
     1      10047.92
     2      10096.06
     3      10144.44
     4      10193.05
     5      10241.89
     6      10290.97
     7      10340.28
     8      10389.82
     9      10439.61
     10     10489.63
     11     10539.89
     12     10590.40
     13     10641.14
     14     10692.13
     15     10743.37
     16     10794.84
     17     10846.57
     18     10898.54
4. (25 points) Problem 5.43 of the book. Math: combinations. Write a program that displays all possible combinations for picking two numbers from integers 1 to 7. Also display the total number of all combinations.
   • Name the file and program ch5pr43.java.
   • Example execution (java ch5pr43):
     
     1 2
     1 3
     1 4
     1 5
     1 6
     1 7
     2 3
     2 4
     2 5
     2 6
     2 7
     3 4
     3 5
     3 6
     3 7
     4 5
     4 6
     4 7
     5 6
     5 7
     6 7
     
     The total number of all combinations is 21
5. Bonus. (10 points) Problem 5.17 of the book. Display pyramid. Write a program that prompts the user to enter an integer from 1 to 15 and displays a pyramid like below.
   • Name the file and program ch5pr17.java.
   • Example execution (java ch5pr17) user provides input:
     
     Enter the number of lines: 7
                               1
                           2   1   2
                       3   2   1   2   3
                   4   3   2   1   2   3   4
               5   4   3   2   1   2   3   4   5
           6   5   4   3   2   1   2   3   4   5   6
       7   6   5   4   3   2   1   2   3   4   5   6   7