Josephus solution in Groovy

Josephus.groovy

class Josephus {
    void execute(size = 41, steps = 3, survivors = 2) {
        def prisoners = (1..size).toArray()

        while(prisoners.length > survivors) {
            (steps-1).times {
                prisoners = prisoners.tail() + prisoners.head()
            }
            // Execute first prisoner
            prisoners = prisoners.tail()
        }

        println("${prisoners.length} prisoners left")
        println(prisoners)
    }
}