java : here is a code that I have to implement. counting the occuence in an array

/**  * _Part 3: Implement this method._  *  * Counts the items in the ordered array list that are equal to the item at  * the specified index. Be sure to take advantage of the fact that the list  * is sorted here. You should not have to run through the entire list to  * make this count.  *  * @param index an index in the range 0..(size-1)  * @return the number of items in the list equal to the item returned by  * get(index)  */ public int countEquivalent ( int index ) { for (int i = 0; i < array.length; i++) { array[index] = array[i]; for (int j = 0; j < array.length; j++) { if (array[j]!=array[counter]) { return j; } } } return counter; }