Add files via upload

Author: muthusk07

boyer_moore.cpp

@@ -0,0 +1,54 @@
+#include <bits/stdc++.h> 
+using namespace std; 
+# define NO_OF_CHARS 256  
+  
+void badCharHeuristic( string str, int size,  
+                        int badchar[NO_OF_CHARS])  
+{  
+    int i;  
+  
+    for (i = 0; i < NO_OF_CHARS; i++)  
+        badchar[i] = -1;  
+  
+    for (i = 0; i < size; i++)  
+        badchar[(int) str[i]] = i;  
+}  
+ 
+void search( string txt, string pat)  
+{  
+    int m = pat.size();  
+    int n = txt.size();  
+  
+    int badchar[NO_OF_CHARS];  
+  
+    badCharHeuristic(pat, m, badchar);  
+  
+    int s = 0; 
+    while(s <= (n - m))  
+    {  
+        int j = m - 1;  
+  
+        while(j >= 0 && pat[j] == txt[s + j])  
+            j--;  
+  
+        if (j < 0)  
+        {  
+            cout << "pattern occurs at shift = " <<  s << endl;  
+  
+            s += (s + m < n)? m-badchar[txt[s + m]] : 1;  
+  
+        }  
+  
+        else
+            s += max(1, j - badchar[txt[s + j]]);  
+    }  
+}  
+  
+/* main func*/
+int main()  
+{  
+    string txt= "ABAAABCD";  
+    string pat = "ABC";  
+    search(txt, pat);  
+    return 0;  
+}