Merge Sort - Natural Merge Sort

Natural Merge Sort

A natural merge sort is similar to a bottom up merge sort except that any naturally occurring runs (sorted sequences) in the input are exploited. In the bottom up merge sort, the starting point assumes each run is one item long. In practice, random input data will have many short runs that just happen to be sorted. In the typical case, the natural merge sort may not need as many passes because there are fewer runs to merge. For example, in the best case, the input is already sorted (i.e., is one run), so the natural merge sort need only make one pass through the data.