Instructor Demo Programming Problems

Problem D1

Write a program to find the sum of the first n positive integers.  Your program should read values of n (whole numbers) one per line from standard input (without prompting) and send the results to standard output, one per line. You may assume the input is a whole number, but it may be non-positive.

Problem D2

Write a program to read a list of whole numbers.  Find the product of all the positive numbers, the sum of all the negative numbers, and the count of the number of zeroes. Your program should read the list of numbers on one line from standard input (without prompting) and send the results to standard output.  Order the results: product, sum, count and leave one blank between them.

Problem D3

Write a program to find the position of the first and last 9 in a list of whole numbers. Your program should read the list of numbers on one line from standard input (without prompting) and send the results to standard output.  Order the results: first position, last position and leave one blank between them.

Problem D4

Write a program to compute the percentage of comment lines in a Java source code file. A comment line is one whose first non-blank character is a slash or an asterisk.  Ignore blank lines.