CPKit
v1.6.1

Optimal Merge Pattern

GreedyMedium

Construct optimal merge trees using min-priority queues.

Alt+Shift+O

Configuration Panel

Optimal Merge Pattern Decision Tree

Double-click empty canvas to create root, select node to add child or delete.

Time Complexity

O(N log N) with priority queue

Space Complexity

O(N) tree size memory
Conceptual Overview

The Optimal Merge Pattern problem finds the most efficient way to merge a set of sorted files into a single sorted file, minimizing total record comparison movements.

Greedy Choice Property

Repeatedly extract the two files of smallest sizes from a min-priority queue, merge them (cost = sum of sizes), and insert the resulting file back.

Optimal Substructure

An optimal merge pattern for N files consists of merging the two smallest files first, then solving the remaining N-1 file merges optimally.

Proof Idea / Correction

Proof by Huffman coding equivalence: since record movements are weighted by the depth of leaf files, placing larger files closer to the root (merging them last) minimizes total weighted depth.

Source: CP-Algorithms greedy reference