Java and Algorithm problem. Please show all the steps and comments to solve it.

Given a sorted array of integer, A, with possible duplicate elements. Implement an efficient function in Java to find in A, the numbers of occurrences of the input value k. For example, in an array A = {-1, 2, 3, 5, 6, 6, 6, 9, 10} and k = 6, your program should return 3. What is the running time complexity of your function? Justify