Lab 6

Due 9:40AM October 20, 2008

1. Implement and test a method that uses tail recursion to convert an array of integers into their absolute values.
2. Design and implement a recursive program to produce the following output:
   0
   0 1
   0 1 2
   0 1 2 3
   0 1 2 3 4
   0 1 2 3
   0 1 2
   0 1
   0
   Your program should prompt the user for the total number of rows she wishes to print.  You may not use any loops in the this program.
3. Design and implement a recursive program to print all permutations of a given string. For instance, given the string "hat" your program should print the strings "tha", "aht", "tah", "ath", "hta", and "hat".