Solve in C++

The array a(1..n) contains sorted integers. Write a function marlin (a, n) that returns the length of the longest sequence of identical numbers (for example, if a = (1, 1, 1, 2, 3, 3, 5, 6, 6, 6, 6, 7, 9) then marlin returns 4 because the longest sequence 6, 6, 6, 6 contains 4 numbers. Write a demo main program for testing the work of marlin. Explain your solution, and insert comments in your program. The solution should have time complexity O(n)