Sure. The Java code describes the computation you want done, just like the math-like definition of Triangle.
class TriangleCalc
{
public int Triangle( int N )
{
if ( N == 1 )
return 1;
else
return N + Triangle( N-1 );
}
}
public class TriangleTester
{
public static void main ( String[] args)
{
TriangleCalc tri = new TriangleCalc();
int result = tri.Triangle( 4 );
System.out.println("Triangle(4) is " + result );
}
}
The above program tests this method. The value for N is hard-coded. Here is the output of the program:
C:\JavaSource>java TriangleTester Triangle(4) is 10
Of course, it would be worth while to copy this program
to a file and run it.
You might wish to
improve the program so that N is entered by the user.
If you do, have main() test that N
is positive before it calls Triangle.
There is a formula that gives the value of
Triangle(N) in one step.
But let us continue with the recursive definition.
What is Triangle(500)?