Updated algorithms and improved documentation

BinaryToDecimal.py

@@ -20,15 +20,30 @@ def decToBin(decNum): #function created to convert decimal to binary with parame
 	return binNum
 
 def convert(fromNum, fromBase, toBase): #function for converting from any base to any other base
+	# Step 1: Convert fromNum (represented as an integer using digits of fromBase) to a standard base 10 integer
+	val = 0
+	power = 0
+	temp = fromNum
+	while temp > 0:
+		digit = temp % 10
+		if digit >= fromBase:
+			raise ValueError(f"Digit {digit} is invalid for base {fromBase}")
+		val += digit * (fromBase ** power)
+		temp //= 10
+		power += 1
+
+	# Step 2: Convert standard base 10 integer to the target base (represented using base 10 digits)
 	toNum = 0
 	power = 0
-	while fromNum > 0:
-		toNum += fromBase ** power * (fromNum % toBase)
-		fromNum //= toBase
+	while val > 0:
+		digit = val % toBase
+		toNum += digit * (10 ** power)
+		val //= toBase
 		power += 1
 	return toNum
 
-# print (str(binToDec(101011)))
-# print (str(decToBin(128)))
-print (str(convert(127, 10, 8)))	# converts 127 in  base 10 to base 8
-print (str(convert(101001, 2, 2)))	
+print("101011 in base 2 to base 10: " + str(binToDec(101011)))
+print("128 in base 10 to base 2: " + str(decToBin(128)))
+print("127 in base 10 to base 8: " + str(convert(127, 10, 8)))	# converts 127 in base 10 to base 8
+print("177 in base 8 to base 2: " + str(convert(177, 8, 2)))	# converts 177 in base 8 to base 2
+

DepthFirstSearch.py

@@ -13,8 +13,9 @@ def add_neighbor(self, v):
 			self.neighbors.sort()
 
 class Graph:
-	vertices = {}
-	time = 0
+	def __init__(self):
+		self.vertices = {}
+		self.time = 0
 
 	def add_vertex(self, vertex):
 		if isinstance(vertex, Vertex) and vertex.name not in self.vertices:
@@ -39,20 +40,18 @@ def print_graph(self):
 			print(key + str(self.vertices[key].neighbors) + "  " + str(self.vertices[key].discovery) + "/" + str(self.vertices[key].finish))
 
 	def _dfs(self, vertex):
-		global time
 		vertex.color = 'red'
-		vertex.discovery = time
-		time += 1
+		vertex.discovery = self.time
+		self.time += 1
 		for v in vertex.neighbors:
 			if self.vertices[v].color == 'black':
 				self._dfs(self.vertices[v])
 		vertex.color = 'blue'
-		vertex.finish = time
-		time += 1
+		vertex.finish = self.time
+		self.time += 1
 
 	def dfs(self, vertex):
-		global time
-		time = 1
+		self.time = 1
 		self._dfs(vertex)
 
 g = Graph()

HashMap.py

@@ -49,7 +49,8 @@ def keys(self):
                 arr = []
                 for i in range(0, len(self.map)):
                         if self.map[i]:
-                                arr.append(self.map[i][0])
+                                for pair in self.map[i]:
+                                        arr.append(pair[0])
                 return arr
 
         def print(self):

HexToDec.py

@@ -1,18 +1,22 @@
 # Python Hexadecimal to Decimal Conversion
 
 def __getDecDigit(digit):
-	digits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 
-		'A', 'B', 'C', 'D', 'E', 'F']
-	for x in range(len(digits)):
-		if digit == digits[x]:
-			return x
+	digits = {
+		'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9, 
+		'A': 10, 'B': 11, 'C': 12, 'D': 13, 'E': 14, 'F': 15
+	}
+	return digits.get(digit.upper())
 
 def hexToDec(hexNum):
 	decNum = 0
 	power = 0
 	for digit in range(len(hexNum), 0, -1):
-		decNum = decNum + 16 ** power * __getDecDigit(hexNum[digit-1])
+		val = __getDecDigit(hexNum[digit-1])
+		if val is None:
+			raise ValueError(f"Invalid hexadecimal digit: {hexNum[digit-1]}")
+		decNum = decNum + 16 ** power * val
 		power += 1
-	print(str(decNum))
+	return decNum
 
-hexToDec("A5")
+print("A5 in decimal: " + str(hexToDec("A5")))
+print("3c in decimal: " + str(hexToDec("3c")))

MaxHeap.py

@@ -3,19 +3,20 @@
 # private functions: __swap, __floatUp, __bubbleDown
 
 class MaxHeap:
-	def __init__(self, items=[]):
+	def __init__(self, items=None):
 		super().__init__()
 		self.heap = [0]
-		for i in items:
-			self.heap.append(i)
-			self.__floatUp(len(self.heap) - 1)
+		if items is not None:
+			for i in items:
+				self.heap.append(i)
+				self.__floatUp(len(self.heap) - 1)
 
 	def push(self, data):
 		self.heap.append(data)
 		self.__floatUp(len(self.heap) - 1)
 
 	def peek(self):
-		if self.heap[1]:
+		if len(self.heap) > 1:
 			return self.heap[1]
 		else:
 			return False
@@ -56,5 +57,15 @@ def __bubbleDown(self, index):
 
 m = MaxHeap([95, 3, 21])
 m.push(10)
-print(str(m.heap[0:len(m.heap)]))
-print(str(m.pop()))
+print("Heap state:", m.heap)
+print("Peek top:", m.peek())
+print("Popped:", m.pop())
+print("Peek top after pop:", m.peek())
+
+# Test empty heap peek
+empty_heap = MaxHeap()
+print("Empty heap peek:", empty_heap.peek())
+
+# Test heap with 0
+heap_with_zero = MaxHeap([0])
+print("Zero heap peek:", heap_with_zero.peek())

Queues_implementation.py

@@ -0,0 +1,116 @@
+# Queue Implementation in Python
+# This file includes two queue implementations:
+# 1. LinkedListQueue: using a custom Node class.
+# 2. ArrayQueue: using Python's built-in list.
+
+class Node:
+    """A class representing a node in a linked list queue."""
+    def __init__(self, item=None):
+        self.item = item
+        self.next = None
+        self.previous = None
+
+
+class LinkedListQueue:
+    """A Queue implementation using a doubly linked list."""
+    def __init__(self):
+        self.length = 0
+        self.head = None
+        self.tail = None
+
+    def enqueue(self, x):
+        """Add an element to the back of the queue."""
+        new_node = Node(x)
+        if self.head is None:
+            self.head = self.tail = new_node
+        else:
+            self.tail.next = new_node
+            new_node.previous = self.tail
+            self.tail = new_node
+        self.length += 1
+
+    def dequeue(self):
+        """Remove and return the front element of the queue."""
+        if self.is_empty():
+            raise IndexError("dequeue from empty queue")
+        item = self.head.item
+        self.head = self.head.next
+        if self.head is not None:
+            self.head.previous = None
+        self.length -= 1
+        if self.length == 0:
+            self.tail = None
+        return item
+
+    def is_empty(self):
+        """Return True if the queue is empty, False otherwise."""
+        return self.length == 0
+
+    def size(self):
+        """Return the number of elements in the queue."""
+        return self.length
+
+    def display(self):
+        """Return a list representation of the queue from front to back."""
+        arr = []
+        current = self.head
+        while current:
+            arr.append(current.item)
+            current = current.next
+        return arr
+
+
+class ArrayQueue:
+    """A Queue implementation using a dynamic array (Python list)."""
+    def __init__(self):
+        self.items = []
+
+    def is_empty(self):
+        """Return True if the queue is empty, False otherwise."""
+        return len(self.items) == 0
+
+    def enqueue(self, data):
+        """Add an element to the back of the queue."""
+        self.items.append(data)
+
+    def dequeue(self):
+        """Remove and return the front element of the queue."""
+        if self.is_empty():
+            raise IndexError("dequeue from empty queue")
+        return self.items.pop(0)
+
+    def size(self):
+        """Return the number of elements in the queue."""
+        return len(self.items)
+
+    def display(self):
+        """Return a list representation of the queue from front to back."""
+        return list(self.items)
+
+
+def main():
+    print("--- Testing ArrayQueue ---")
+    que = ArrayQueue()
+    que.enqueue('google')
+    que.enqueue('youtube')
+    que.enqueue('udemy')
+    que.enqueue('udacity')
+    print("Initial queue:", que.display())
+    print("Dequeued:", que.dequeue())
+    print("Dequeued:", que.dequeue())
+    print("Remaining queue:", que.display())
+
+    print("\n--- Testing LinkedListQueue ---")
+    ll_que = LinkedListQueue()
+    ll_que.enqueue('google')
+    ll_que.enqueue('youtube')
+    ll_que.enqueue('udemy')
+    ll_que.enqueue('udacity')
+    print("Initial queue:", ll_que.display())
+    print("Dequeued:", ll_que.dequeue())
+    print("Dequeued:", ll_que.dequeue())
+    print("Remaining queue:", ll_que.display())
+
+
+if __name__ == "__main__":
+    main()

README.md

@@ -1,19 +1,20 @@
-#This is a open source project.
-# Python 3
-These files are mainly intended to accompany my series of YouTube tutorial videos here, 
+# Python 3 Examples
+
+This is an open source project. These files are mainly intended to accompany my series of YouTube tutorial videos here:
 https://www.youtube.com/user/joejamesusa
-and are mainly intended for educational purposes.
-You are invited to subscribe to my video channel-Joe James, and to download and use any code in 
-this Python repository, according to the MIT License. 
-Feel free to post any comments on my YouTube channel.
-I am very happy to see you there on my you tube channel. excited!!!!!!!!!
-## Subscribe to my channel for more tutorial videos. 
-
-This source code is easy to understand and reliable for self study and you will learn them easily, try to practice more coding by making algorithms yourself and you can become a better Python programmer, and remember "Try to learn something about everything and everything about something".
-
-Thank you for reviewing my repositories and keep practicing.
-Joe James.
-Fremont, CA.
+
+The examples are mainly intended for educational purposes. You are invited to subscribe to my video channel (Joe James) and to download and use any code in this Python repository according to the MIT License. Feel free to post any comments on my YouTube channel.
+
+I am very happy to see you there on my YouTube channel!
+
+## Subscribe to my channel for more tutorial videos
+
+This source code is easy to understand and reliable for self-study, helping you learn concepts easily. Try to practice more coding by designing algorithms yourself to become a better Python programmer. Remember: "Try to learn something about everything and everything about something."
+
+Thank you for reviewing my repository, and keep practicing!
+
+Joe James  
+Fremont, CA  
 Copyright (C) 2015-2021, Joe James
 
-## Happy coding guys!😀
+## Happy coding! 💻