From 79b85c3d4f3d01ea8e0eb8f41652a554974b1cf1 Mon Sep 17 00:00:00 2001
From: KavishanSukumar <kavishansukumar@gmail.com>
Date: Wed, 20 Oct 2021 16:54:26 +0530
Subject: [PATCH] Adding Boyer-MooreHorspool Algorithm for string matching in
 python language

---
 .../Boyer-MooreHorspoolAlgorithm.py           | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 String Algorithms/String Matching/Boyer-MooreHorspoolAlgorithm.py

diff --git a/String Algorithms/String Matching/Boyer-MooreHorspoolAlgorithm.py b/String Algorithms/String Matching/Boyer-MooreHorspoolAlgorithm.py
new file mode 100644
index 0000000..54b9913
--- /dev/null
+++ b/String Algorithms/String Matching/Boyer-MooreHorspoolAlgorithm.py	
@@ -0,0 +1,48 @@
+import os
+
+CHAR=256
+
+def badCharacterTable(pattern):
+    length=len(pattern)
+    badchar=[length]*CHAR
+    
+    for i in range(length-1):
+        badchar[ord(pattern[i])]=length-i
+    
+    return badchar
+
+def stringSearch(text,pattern):
+    textlen=len(text)
+    patternlen=len(pattern)
+    badchar=badCharacterTable(pattern)    
+    occurance=[]
+    position=0
+    if(text=="" or pattern==""):
+        print("Text:"+text+"\nPattern:"+pattern+"\nTotal Number matched:"+str(len(occurance))+"\nPositions matched:"+', '.join(occurance))
+        return
+    
+    while(position<=(textlen-patternlen)):
+        j=patternlen-1
+        while(j>=0 and (text[position+j]==pattern[j] or pattern[j]=='_')):
+            j=j-1
+            
+        if(j==-1):
+            occurance.append(str(position+1))
+            position=position+1
+        else:
+            position=position+ max(1,j-badchar[ord(text[position+j])])
+    print("Text:"+text+"\nPattern:"+pattern+"\nTotal Number matched:"+str(len(occurance))+"\nPositions matched:"+', '.join(occurance))
+        
+def main():
+    while (1):
+        text=input("Enter a sample text:")
+        pattern=input("Enter a pattern:")
+        stringSearch(text,pattern)
+        print("\nEnter 1 to test Continue\nEnter 0 to EXIT")
+        n=input("Enter your choise: ")
+        if(n=='0'):
+            return
+
+
+if __name__=="__main__":
+    main()