Groovy example source code file (heapsort.groovy)

This example Groovy source code file (heapsort.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

ia, ia, ic, ic, im, im, n, n+1, n+1

The Groovy heapsort.groovy source code

/*
	The Computer Language Shootout
	http://shootout.alioth.debian.org/

	contributed by Jochen Hinrichsen
*/
    public static final long IM = 139968
    public static final long IA =   3877
    public static final long IC =  29573

    public static long last = 42
    def gen_random(double max) {
		max * (last = (last * IA + IC) % IM) / IM
    }

    def heapsort(int n, double[] ra) {
		int l, j, ir, i
		double rra

		l = (n >> 1) + 1
		ir = n
		while (true) {
		    if (l > 1) {
				rra = ra[--l]
		    } else {
				rra = ra[ir]
				ra[ir] = ra[1]
				if (--ir == 1) {
				    ra[1] = rra
				    return
				}
		    }
		    i = l
		    j = l << 1
		    while (j <= ir) {
				if (j < ir && ra[j] < ra[j+1]) { ++j }
				if (rra < ra[j]) {
				    ra[i] = ra[j]
				    j += (i = j)
				} else {
				    j = ir + 1
				}
		    }
		    ra[i] = rra
		}
    }

def N = (args.length == 0) ? 1000 : args[0].toInteger()
def nf = java.text.NumberFormat.getInstance()
nf.setMaximumFractionDigits(10)
nf.setMinimumFractionDigits(10)
nf.setGroupingUsed(false)
double []ary = (double[]) java.lang.reflect.Array.newInstance(double.class, N+1)
for (i in 0..<N) {
    ary[i] = gen_random(1)
}
heapsort(N, ary)
println nf.format(ary[N])

// EOF