i have a couple of questions on java for my homework

21229

Assume the availability of a method named makeLine that can be passed a non-negative integer n and a character c and return a String consisting of n identical characters that are all equal to c. Write a method named printTriangle that receives two integer parameters n andk. If n is negative the method does nothing. If n happens to be an even number, its value is raised to the next odd number (e.g. 4-->5). Then, when k has the value zero, the method prints a SYMMETRIC triangle of O's (the capital letter O) as follows: first a line of n O, followed by a line of n-2 O's (indented by one space), and then a line of n-4 O's (indented by two spaces), and so on. For example, if the method received 5,0 (or 4,0) it would print:
OOOOO
OOO
O
Note: in the above output , the first line contains 0 spaces before the first O, the next line 1 space, and so on.
Note: These instructions state what the method does when k is zero, but it is up to you, the programmer, to determine what it does when k is not zero and use it for your advantage.
The method must not use a loop of any kind (for, while, do-while) to accomplish its job. The method should invoke makeLine to accomplish the task of creating Strings of varying lengths.

20861

A palindrome is a string that reads the same forwards or backwards; for example dad, mom, deed (i.e., reversing a palindrome produces the same string ). Write a recursive, boolean -valued method , isPalindrome that accepts a string and returns whether the string is a palindrome.
A string , s, is a palindrome if:

• s is the empty string or s consists of a single letter (which reads the same back or forward), or
• the first and last characters of s are the same, and the rest of the string (i.e., the second through next-to-last characters ) form a palindrome.

20864

A 'array palindrome' is an array which, when its elements are reversed, remains the same (i.e., the elements of the array are same when scanned forward or backward) Write a recursive, boolean -valued method , isPalindrome, that accepts an integer -valued array , and a pair ofintegers representing the starting and ending indexes of the portion of the array to be tested for being a palindrome. The function returnswhether that portion of the array is a palindrome.
An array is a palindrome if:

• the array is empty (0 elements ) or contains only one element (which therefore is the same when reversed), or
• the first and last elements of the array are the same, and the rest of the array (i.e., the second through next-to-last elements ) form a palindrome.