CS201 – Spring 2003

Prof. Hartman

Homework #3

Due Friday, February 7^th by 5:00 pm

Homework to be turned in (remember that all programs must follow the guidelines from handout #3.)

1) Write a program to print the following:
x x
x x
x x
x
x x
x x
x x
Your program should use only output statements that print a single ‘x’ or a single space. Use loops to make your code concise. (Hint: Use two nested loops, with an ‘if’ test to decide whether to print an ‘x’ or a space.)

2) Write a program that inputs an integer (we’ll call it n) and then inputs n integers and outputs the largest two of these. If the value of n given by the user is not reasonable, handle this gracefully.

3) Write a program to input two integers x and y, and print out an x-by-y rectangle of asterisks. (Problem 3 on the last assignment had you print out a 4-by-7 rectangle of asterisks. If you solved this with for loops then this problem will only be three or four lines more.) Don’t forget to handle bad input gracefully.

4) Write a program that inputs a positive integer (handle errors gracefully) and then prints the following sequence of numbers. The first number is the number that was input. Each successive number is obtained in one of two ways. If the previous number is odd, multiply it by 3 and add 1. If the previous number is even, divide it by 2. The sequence ends when 1 is reached. For example, if the number 12 is entered, the program should print
12, 6, 3, 10, 5, 16, 8, 4, 2, 1

5) Write a program that repeatedly inputs a number from 1 to 9 (handle errors gracefully) then prints out the number as a word (“one”, “two”, etc.). The program should terminate when the sentinel value 0 is input.