This is helpful ppt based on boyer moore algorithm

1. Boyer-Moore Algorithm
Efficient String Matching Technique

2. Introduction
• The Boyer-Moore algorithm is a string
searching algorithm that improves the
efficiency of pattern matching in texts.
Developed by Robert S. Boyer and J Strother
Moore in 1977.

3. Key Concepts
• - Bad Character Heuristic
• - Good Suffix Heuristic
• - Skipping sections of text for faster matching

4. Bad Character Heuristic
• If a mismatch occurs, the pattern is shifted
such that the mismatched character in the
text aligns with the last occurrence in the
pattern, or pattern moves past it.

5. Good Suffix Heuristic
• If a suffix of the pattern matches, and a
mismatch occurs before the suffix, shift the
pattern to align the next matching suffix.

6. Algorithm Steps
• 1. Preprocess pattern for bad character and
good suffix tables
• 2. Align pattern with text
• 3. Compare from right to left
• 4. If mismatch, use heuristics to shift
• 5. Repeat until end of text

7. Advantages
• - Efficient for long patterns
• - Often skips large parts of text
• - Used in practical applications like grep

8. Applications
• - Text editors and search utilities
• - DNA sequence analysis
• - Network security and malware detection

9. Summary
• The Boyer-Moore algorithm is a fast and
powerful technique for string searching.
• It is based on two main heuristics that allow
skipping sections of the text efficiently.

10. Thank You
• Questions?