string match | computer science
TRANSCRIPT
STRING MATCH
DEFINITION AND CLASSIFICATION OF STRING MATCHING
A string is given to be matched with a long text (or a string) and at this point of string matching, either a single string or multiple strings can be asked to match
Based on number of strings to be matched, Pattern (nothing but a string) matching algorithms are classified as 1. Single pattern matching algorithms
and 2. Multiple pattern matching algorithms
SOME REAL WORLD PROBLEMS THAT NEED STRING MATCHFinger prints and Retinal scans in
high security systems like banking security
DNA analysis and Bio Informatics
Computer password matching
Cyber Forensics department
HOW DOES A PROBLEM LOOK LIKE!TEXT: A B A C B A B C A C A B
Pattern:A C B (NOT Matched initially)
_ A C B (Not matched on first shift)
_ _ A C B (matched on second shift)
In real world, when you enter your password while you sign in your twitter account, password entered by you is matched with string in their database
DIFFERENT ALGORITHMS WITH DIFFERENT APPROACHESThere are many algorithms in order to solve the problems facing in String matching.
Each algorithm has its own way of matching the strings. Some match in an optimal time with minimum number of comparisons while some take very long time.
SOME WELL KNOWN ALGORITHMS Rabin-Karp String matching algorithms
Naïve string matching algorithm
Knuth-Morris-Pratt algorithm also better known as “KMP”
Brute force comparison technique is used by Rabin-Karp and
makes comparisons only if hash values in both the text and
string are same.
SUMMARY
• String match and its types
• Some well known algorithms to do string matching
• Application of string matching in real world problems
• Scenario of string matching
Hey Friends,This was just a summary on String Match. For more detailed information on this topic, please type the link given below or copy it from the description of this PPT and open it in a new browser window.
www.transtutors.com/homework-help/computer-science/string-match.aspx