Java Method

It might be nice to have a Java method that does the calculation for us. Assume that N is a positive integer. Here is a math-like definition of Triangle(N):

• Triangle( 1 ) = 1
• Triangle( N ) = N + Triangle( N-1 )

And here is a Java method that does this calculation:

public int Triangle( int N )
{
  if ( N == 1 )
    return 1;
  else
    return N + Triangle( N-1 );
}

The Java code is similar to the math-like definition of Triangle(). The if statement detects the base case and immediately returns its value. Both the Java code and the math-like definition assume that N is positive.