how to get a section of an array in java
//index 0 1 2 3 4
int[] arr = {10, 20, 30, 40, 50};
Arrays.copyOfRange(arr, 0, 2); // returns {10, 20}
Arrays.copyOfRange(arr, 1, 4); // returns {20, 30, 40}
Arrays.copyOfRange(arr, 2, arr.length); // returns {30, 40, 50} (length = 5)