Plagiarism Checker

Author: Jade Chan, Date: Nov 11, 2015

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SUMMARY

This program checks the similarity of two files, accounting for synomyms.

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COMPILE & RUN

g++ plagiarism_checker.cpp -o plagiarism_checker
./plagiarism_checker synonyms.txt file1.txt file2.txt

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SOLUTION

This program first reads through the synonyms file, and hashes then accordingly. It takes the words in each line, and hashes them as the key, with the value being the first word in that line.

For example, the line "run sprint jog" is hashed as
	   key : value
	----------------
	sprint : run
	   jog : run

Then, it equates the synonyms, writing them to be the same word. The words in each input file are then read through, and checked if they are one of the hashed words. If they are — they are replaced by the first word in the line of synonyms.

For example, the line 
	"go for a jog" 

is replaced with 
	"go for a run"

The words are then concatenated into 1 string according to the tuples count.

The two files are then checked against each other, and the percentage is generated.

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DATA STRUCTURES USED

1. Hashmap: This was used to store each synonym and the key. This data structure was chosen as it provides constant time for the lookup for a word.

2. Vectors: This was used to store all the words in a file. This data structure was chosen as the words in a file only need to be traversed linearly. Access to the middle of the vector was not necessary.

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ALGORITHMIC COMPLEXITY & RUNTIME

This program currently runs on n^2 time, as there are 2 doubly-nested for-loops in the exists, and parsing_tuples function.