Shell Sort - Performance

This section provides a tutorial on how to measure the performance of the Shell Sort algorithm. My first Java implementation of Shell Sort is performing somewhere between O(N*Log2(N) and O(N*N) order levels.

Now let's see how my Java implementation of the Shell Sort algorithm performs. I tried this implementation with my SortTest.java under JDK 1.3.1. Here are the results:

Array size: 10000
Average sorting time: 25 milliseconds
Number of tests: 1000
Performance: 2.5 O(N) nanoseconds
Performance: 0.18814374728998823 O(N*Log2(N)) nanoseconds
Performance: 2.5E-4 O(N*N) nanoseconds

Array size: 20000
Average sorting time: 81 milliseconds
Number of tests: 1000
Performance: 4.05 O(N) nanoseconds
Performance: 0.28346035337307884 O(N*Log2(N)) nanoseconds
Performance: 2.025E-4 O(N*N) nanoseconds

Array size: 30000
Average sorting time: 148 milliseconds
Number of tests: 1000
Performance: 4.933333333333334 O(N) nanoseconds
Performance: 0.3317045099854675 O(N*Log2(N)) nanoseconds
Performance: 1.6444444444444444E-4 O(N*N) nanoseconds

As you can see, the performance of this Shell Sort is much better than Insertion sort. But it is still not as good as Quicksort.

Last update: 2011.

Table of Contents

 About This Book

 Introduction of Sorting Algorithms

 Java API for Sorting Algorithms

 Insertion Sort Algorithm and Implementation

 Selection Sort Algorithm and Implementation

 Bubble Sort Algorithm and Implementation

 Quicksort Algorithm and Implementation

 Merge Sort Algorithm and Implementation

 Heap Sort Algorithm and Implementation

Shell Sort Algorithm and Implementation

 Shell Sort - Algorithm Introduction

 Shell Sort - Java Implementation

Shell Sort - Performance

 Shell Sort - Implementation Improvements

 Performance Summary of Java Implementations

 References

 PDF Printing Version