greedy_methods.optimal_merge_pattern

This is a pure Python implementation of the greedy-merge-sort algorithm reference: https://www.geeksforgeeks.org/optimal-file-merge-patterns/

For doctests run following command: python3 -m doctest -v greedy_merge_sort.py

Objective Merge a set of sorted files of different length into a single sorted file. We need to find an optimal solution, where the resultant file will be generated in minimum time.

Approach If the number of sorted files are given, there are many ways to merge them into a single sorted file. This merge can be performed pair wise. To merge a m-record file and a n-record file requires possibly m+n record moves the optimal choice being, merge the two smallest files together at each step (greedy approach).

Functions

optimal_merge_pattern(→ float)

Function to merge all the files with optimum cost

Module Contents

greedy_methods.optimal_merge_pattern.optimal_merge_pattern(files: list) → float

Function to merge all the files with optimum cost

Args:

files [list]: A list of sizes of different files to be merged

Returns:

optimal_merge_cost [int]: Optimal cost to merge all those files

Examples: >>> optimal_merge_pattern([2, 3, 4]) 14 >>> optimal_merge_pattern([5, 10, 20, 30, 30]) 205 >>> optimal_merge_pattern([8, 8, 8, 8, 8]) 96