Files for binary tree and string chapter

Files for binary tree and string chapter uploaded.

Author: Hemant-Jain-Author

BinaryTree/Tree.py

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>PyString</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.python.pydev.PyDevBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.python.pydev.pythonNature</nature>
+	</natures>
+</projectDescription>

String/.project

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+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<?eclipse-pydev version="1.0"?><pydev_project>
+<pydev_pathproperty name="org.python.pydev.PROJECT_SOURCE_PATH">
+<path>/${PROJECT_DIR_NAME}</path>
+</pydev_pathproperty>
+<pydev_property name="org.python.pydev.PYTHON_PROJECT_VERSION">python 2.7</pydev_property>
+<pydev_property name="org.python.pydev.PYTHON_PROJECT_INTERPRETER">Default</pydev_property>
+</pydev_project>

String/.pydevproject

@@ -0,0 +1,100 @@
+#!/usr/bin/env python
+    
+def BruteForceSearch(text, pattern):
+    i = 0
+    n = len(text)
+    m = len(pattern)
+    while i <= n - m:
+        j = 0
+        while j < m and pattern[j] == text[i + j]:
+            j += 1
+        if j == m:
+            return i
+        i += 1
+    return -1
+   
+def RobinKarp(text, pattern):
+    n = len(text)
+    m = len(pattern)
+    prime = 101
+    powm = 1
+    TextHash = 0
+    PatternHash = 0
+    if m == 0 or m > n:
+        return -1
+    i = 0
+    while i < m - 1:
+        powm = (powm << 1) % prime
+        i += 1
+    i = 0
+    while i < m:
+        PatternHash = ((PatternHash << 1) + ord(pattern[i])) % prime
+        TextHash = ((TextHash << 1) + ord(text[i])) % prime
+        i += 1
+    i = 0
+    while i <= (n - m):
+        if TextHash == PatternHash:
+            j = 0
+            while j < m:
+                if text[i + j] != pattern[j]:
+                    break
+                j += 1
+            if j == m:
+                return i
+        TextHash = (((TextHash - ord(text[i]) * powm) << 1) + ord(text[i + m])) % prime
+        if TextHash < 0:
+            TextHash = (TextHash + prime)
+        i += 1
+    return -1
+
+def KMPPreprocess(pattern, ShiftArr):
+    m = len(pattern)
+    i = 0
+    j = -1
+    ShiftArr[i] = -1
+    while i < m:
+        while j >= 0 and pattern[i] != pattern[j]:
+            j = ShiftArr[j]
+        i += 1
+        j += 1
+        ShiftArr[i] = j
+
+def KMP(text, pattern):
+    i = 0
+    j = 0
+    n = len(text)
+    m = len(pattern)
+    ShiftArr = [0] * (m + 1)
+    KMPPreprocess(pattern, ShiftArr)
+    while i < n:
+        while j >= 0 and text[i] != pattern[j]:
+            j = ShiftArr[j]
+        i += 1
+        j += 1
+        if j == m:
+            return (i - m)
+    return -1
+
+def KMPFindCount(text, pattern):
+    i = 0
+    j = 0
+    count = 0
+    n = len(text)
+    m = len(pattern)
+    ShiftArr = [0] * (m + 1)
+    KMPPreprocess(pattern, ShiftArr)
+    while i < n:
+        while j >= 0 and text[i] != pattern[j]:
+            j = ShiftArr[j]
+        i += 1
+        j += 1
+        if j == m:
+            count += 1
+            j = ShiftArr[j]
+    return count
+
+st1 = "hello, world!"
+st2 = "world"
+print "BruteForceSearch return : " , BruteForceSearch(st1, st2)
+print "RobinKarp return : " , RobinKarp(st1, st2)
+print "KMP return : " , KMP(st1, st2)