geeeeeeeeek / MyDictionary

Course project for Data Structure and Algorithm. Practice for B tree and Red-Black Tree.

Dictionary with RBT and BT implementations

Course project for Data Structure and Algorithm. Project1. Written in Python!

###I. Analysis work The analysis is followed by these steps:

1. Insert the words in 1_initial.txt into trees
2. Delete the words in 2_delete.txt from trees
3. Add the words in 3_insert.txt
4. Query a word
5. Query some words

and here are some noticeable information:

• In the first three steps, time is counted every 200 piece of data.
• The data source of step 4 is randomly selected words, including some in the tree and some not in the tree.
• The search range in step 5 is from ‘b’ to ‘h’.
• The test procedure and test data set of B tree and Red-Black Tree are virtually the same.
• The time unit is clock.

The table below compares the running time of two data structures.

Clock(s)	B Tree	Red-Black Tree
Step 1: Initialize	0.35945442027343133	0.25324512600334415
Step 2: Delete	0.10402192924312464	10.527893501195248
Step 3: Insert	0.052400542244155246	0.037831793126157365
Step 4: Naïve search	0.0016083440599035104	0.0017657146033887017
Step 5: Range search	0.16599128475087987	1.0174142480211081

Red-Black Tree is roughly competitive as B Tree in insertion and naïve search, and may even be slightly better. However, as deletion and range search are concerned, its speed is far behind B tree. This indicates B tree is more competitive in maintaining large pieces of data.

However, the running time is affected by some implementation details, which may differ from person to person. So the test result may be different compared to that of another implementation.

II. Code Structure

• batch
  • 1_initial.txt
  • 2_delete.txt
  • 4_search.txt
  • i.txt
  • preorder.txt
• core
  • B_Tree.py
  • dal.py
  • RB_Tree.py
• __ init __.py
• AnalysisUtil.py
• DicMain.py
• DicTest.py

The program starts with __ init __.py. batch folder contains given and self-defined test data. core folder contains two tree objects and dal.py. dal.py is a data access layer, which communicates with user interaface and data. DicMain.py and DicTest.py are graphic interfaces for dictionary and vocabulary.

III. Features

The dictionary supports:

• bulk deletions/ insertions from file
• insertion/deletion of a single word
• search a single world
• search in a given range, e.g. ‘apple >> banana’
• switch between B Tree and red-Black Tree
• Bonus feature: vocabulary test. Given a word and select correct meaning from four choices.

Besides, the back-end supports preorder traversal the tree into batch/preorder.txt. Attention: The feature is triggered by __ str __() instead of preoder_traversal()!

Appendix I. Raw data of analysis work

D:\Python34\python.exe D:/Users/Tong/PycharmProjects/MyDictionary/AnalysisUtil.py

# B tree
# Each clock interval for initializing 200 pieces of words.
[4.2763734642473794e-07, 0.01263240721338676, 0.026255222521093212, 0.04007774446958002, 0.05372108636991486, 0.0692019859478368, 0.08541542830018431, 0.1013295245100345, 0.11801849959160633, 0.13304738649435732, 0.15086190307171907, 0.16949662807952345, 0.1897747634096381, 0.2026398053394799, 0.2161924881223727, 0.22882318478637376, 0.2445978712212895, 0.2585482567363573, 0.2720141291379259, 0.28853119400623495, 0.30259362050606603, 0.3181874163434441, 0.3321856972413115, 0.34616644500797544, 0.35945484791077775]
# Each clock interval for deleting 200 pieces of words.
[0.37349974127940544, 0.39492822107140263, 0.41764731037490965, 0.4467920784457948, 0.4775216705225301]
# Each clock time for inserting 200 pieces of words.
[0.5093468694808055, 0.5220335866371882, 0.5348605688431982, 0.5485500955769469, 0.5617474117249608]
# Each clock interval for searching one single word.
[0.5748621938651146, 0.5750208473206382, 0.5752449292901648, 0.5753300291221033, 0.5754121354926168, 0.5754643072488806, 0.5755246041147265, 0.5756037170238151, 0.5756571716921182, 0.5757375675132461, 0.5758051342139812, 0.5758889511338804, 0.5761232963997212, 0.5761985605726919, 0.5762695483721985, 0.5763187266670373, 0.5763986948508187, 0.5764705379250181]
# Clock interval for searching in a range.
[0.57656718396531, 0.7425584687161899]
# Red-Black tree
# Each clock interval for initializing 200 pieces of words.
[0.8197829312829548, 0.8302014599539007, 0.8384450250809303, 0.8477452820909755, 0.8581971664749426, 0.8670962996540413, 0.8771124215820016, 0.8860658647040963, 0.8963052133268903, 0.9051209572234362, 0.9146102299406011, 0.9238424926125648, 0.93657197350359, 0.9486351954088854, 0.9631397989249197, 0.9791954430964365, 0.988812151742836, 0.998426294565157, 1.0094234165658156, 1.018778411156203, 1.0298422445829039, 1.0399657034848167, 1.0522397506018997, 1.0628780848689077, 1.073028057286299]
# Each clock interval for deleting 200 pieces of words.
[1.081706957231989, 3.337879688508957, 6.2202623127482966, 9.68106934994847, 11.609600458427236]
# Each clock time for inserting 200 pieces of words.
[13.672079130014582, 13.680303023823676, 13.690709151011577, 13.699874702257498, 13.70991092314074]
# Each clock interval for searching one single word.
[13.719306543279037, 13.719444670141932, 13.719564836236279, 13.719658916452492, 13.71974145046035, 13.7198432281488, 13.719927900343393, 13.720030533306534, 13.720140008467219, 13.72024991126525, 13.72032432016353, 13.7204355058736, 13.720536000650009, 13.720621100481948, 13.720719884708972, 13.720836629704545, 13.720967486732551, 13.721072257882426]
# Clock interval for searching in a range.
[13.72112785073746, 14.738542098758568]