Method swap

Programs/WiggleSorting.java:7–11

(int[] arr, int a, int b)

    // A utility method to swap two numbers.
    void swap(int[] arr, int a, int b) {
        int temp = arr[a];
        arr[a] = arr[b];
        arr[b] = temp;
    }

    // This function sorts arr[0..n-1] in wave form, i.e.,
    // arr[0] >= arr[1] <= arr[2] >= arr[3] <= arr[4]....