Assume the availability of a method named makeStars that can be passed a non-neg

Question

Assume the availability of a method named makeStars that can be passed a non-negative integer n and print a line of asterisks. Write a method named printTriangle that receives a non-negative integer n and prints a triangle of asterisks as follows: first a line of n asterisks, followed by a line of n-1 asterisks, and then a line of n-2 asterisks, and so on. For example, if the method received 5 it would print: * * * * * * * * * * * * * * * The method must not use a loop of any kind (for, while, do-while) to accomplish its job. The method should invoke printStars to accomplish the task of printing a single line.

Explanation / Answer

The basics of any recursion is to be able to write an expression with what you want on the left as a function of previous values:

f(n) = F( f(n-1) );

and
a stop condition, which for you is
n==0

Although I shouldn't do it (because just getting the answer here lessens the learning experience) the first recursion is easy:

int sum( int[] arr, int len ) {
...if( len == 0 ) return 0;
...return arr[len-1] + sum( arr, len-1 );
}

+add
Corrected an error.

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