Plateau program (max sequence length) (a combinatorial algorithm) The array a(1..n) contains sorted integers. Write a function maxlen(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 maxlen returns 4 because the longest sequence 6,6,6,6 contains 4 numbers. Write a demo main program for testing the work of maxlen. Explain your solution, and insert comments in your program. The solution should have the time complexity O(n).