Exercise:
Write a function which merges two sorted arrays of length n (n ɬ) and m (m ɬ) respectively.
The function fill have the following form:
MERGE (A,p,q,r) /*merges the sorted subarrays A[p...q] and A[q+1…r] to form a single sorted array A[p … r] */
This Algorithm should be off complexity O(n)