package other;

public class interview_arrayshift {
    /**
     * n = 5
     * [1,2,3,4,5] or [5,4,3,2,1]
     * [1,2,3,4,5]: true
     * [3,4,5,1,2]: true
     * *[4,5,1,2,3]: true
     * [5,1,2,3,4]: true
     * [5,4,1,2,3]: false
     * *[3,2,1,5,4]: true
     *
     */

    public static void main (String[] args) {


//        int[] ary = {1,2,3,4,5};
//        int[] ary = {4,5,1,2,3};
//        int[] ary = {4,5,6,7,8,1,2,3};
//        int[] ary = {7,8,4,5,6,1,2,3}; // wrong: double downs

//        int[] ary = {5,4,3,2,1};
//        int[] ary = {3,2,1,5,4};
        int[] ary = {7,6,5,4,3,2,1,9,8};
//        int[] ary = {3,2,1,7,6,5,9,8}; // wrong: double ups

        // append the exact same array to the end
        int[] ary_2 = new int[ary.length * 2];
        for (int i = 0; i < ary.length; i++) {
            ary_2[i] = ary[i];
            ary_2[i + ary.length] = ary[i];
        }

        // ascending
        boolean is_asce_ok = check_asec(ary, ary_2);
        System.out.println("is_asce_ok: " + is_asce_ok);

        // descending
        boolean is_desc_ok = check_desc(ary, ary_2);
        System.out.println("is_desc_ok: " + is_desc_ok);

    }

    private static boolean check_asec(int[] ary, int[] ary_2) {
        int num_start_asec = 1;
        boolean isAsecOK = false;
        for (int i = 0; i < ary_2.length; i++) {
            // found starting number
            if (ary_2[i] == num_start_asec) {
                int i_ary = 0;
                int i_ary_2_tmp = i;
                while (true) {
                    if (i_ary >= ary.length) {
                        isAsecOK = true;
                        break;
                    }
                    if (i_ary_2_tmp >= ary_2.length) break;

                    int val = i_ary + 1;
                    if (ary_2[i_ary_2_tmp] != val) {
                        isAsecOK = false;
                        break;
                    }

                    i_ary++;
                    i_ary_2_tmp++;

                }

            }
            if (isAsecOK) break;
        }
        return isAsecOK;
    }

    private static boolean check_desc(int[] ary, int[] ary_2) {
        int num_start_desc = ary.length;
        boolean isDescOK = false;
        for (int i = 0; i < ary_2.length; i++) {
            if (ary_2[i] == num_start_desc) {

                int i_ary = 0;
                int i_ary_2_tmp = i;
                while (true) {
                    if (i_ary >= ary.length) {
                        isDescOK = true;
                        break;
                    }
                    if (i_ary_2_tmp >= ary_2.length) break;

                    int val = num_start_desc - i_ary;
                    if (ary_2[i_ary_2_tmp] != val) {
                        isDescOK = false;
                        break;
                    }

                    i_ary++;
                    i_ary_2_tmp++;

                }

            }
            if (isDescOK) break;
        }
        return isDescOK;
    }

}