[ReverseNumberArray] #practice

ReverseNumberArray.groovy

class ReverseNumberArray {
    static void main(String[] args) {
        int[] arr = [1, 2, 3, 4, 5, 6, 7, 8, 9]
        println "original: $arr"
        println "reversed: ${reverse(arr, 0, arr.size() - 1)}"
    }

    static int[] reverse(int[] arr, int left, int right) {
        int temp = arr[right]
        arr[right] = arr[left]
        arr[left] = temp
        if (left < right) {
            reverse(arr, ++left, --right)
        }
        arr
    }
}