Create PrefixtoPostFix.py

code/PrefixtoPostFix.py

@@ -0,0 +1,23 @@
+class PrefixToPostFix:
+    def is_operator(self, x):
+        return x in {"-", "+", "/", "*", "^"}
+
+    def convert(self, expression):
+        stack = []
+        for i in range(len(expression) - 1, -1, -1):
+            c = expression[i]
+            if self.is_operator(c):
+                s1 = stack.pop()
+                s2 = stack.pop()
+                temp = s1 + s2 + c
+                stack.append(temp)
+            else:
+                stack.append(c)
+        result = stack.pop()
+        return result
+
+
+if __name__ == "__main__":
+    prefix = "*/93+*24-76"
+    print("Prefix Expression:", prefix)
+    print("Postfix Expression:", PrefixToPostFix().convert(prefix))

final-project/Source.py

@@ -0,0 +1,296 @@
+import os
+import math
+
+class Carriage:
+    def __init__(self):
+	self.carriageType = ""
+	self.carriageID = ""
+	self.carriagePlaces = 0
+
+    def set_data(self, carriageType, carriageID, carriagePlaces):
+	self.carriageType = carriageType
+	self.carriageID = carriageID
+	self.carriagePlaces = carriagePlaces
+
+    def get_carriage_type(self):
+	return self.carriageType
+
+    def get_carriage_id(self):
+	return self.carriageID
+
+    def get_carriage_places(self):
+	return self.carriagePlaces
+
+    def display(self):
+	print("------------------------------------------ ")
+	print("  Carriage: " + self.carriageID + " " + self.carriageType + " " + str(self.carriagePlaces))
+
+class Passenger:
+    def __init__(self):
+	self.firstName = ""
+	self.lastName = ""
+	self.ticketType = ""
+
+    def set_data(self, firstName, lastName, ticketType):
+	self.firstName = firstName
+	self.lastName = lastName
+	self.ticketType = ticketType
+
+    def get_first_name(self):
+	return self.firstName
+
+    def get_last_name(self):
+	return self.lastName
+
+    def get_ticket_type(self):
+	return self.ticketType
+
+    def display(self):
+	print("------------------------------------------ ")
+	print("  Passenger: " + self.firstName + " " + self.lastName + " " + self.ticketType)
+
+class Node:
+    def __init__(self, data):
+	self.data = data
+	self.next = None
+
+class LinkedList:
+    def __init__(self):
+	self.head = None
+
+    def add_node(self, val):
+	new_node = Node(val)
+	if self.head is None:
+	    self.head = new_node
+	else:
+	    temp = self.head
+	    while temp.next is not None:
+		temp = temp.next
+	    temp.next = new_node
+
+    def delete_first(self):
+	if self.head is None:
+	    print("Passengers list is empty!")
+	else:
+	    self.head = self.head.next
+
+    def get_first_element(self):
+	if self.head is not None:
+	    return self.head.data
+
+    def display(self):
+	if self.head is None:
+	    print("Passengers list is empty!")
+	else:
+	    temp = self.head
+	    while temp is not None:
+		print(temp.data, end=" --> ")
+		temp = temp.next
+	    print()
+
+class Stack:
+    def __init__(self):
+	self.front = None
+
+    def push(self, d):
+	new_node = Node(d)
+	if self.front is None:
+	    new_node.next = None
+	else:
+	    new_node.next = self.front
+	    self.front = new_node
+
+    def pop(self):
+	if self.front is None:
+	    print("UNDERFLOW")
+	else:
+	    self.front = self.front.next
+
+    def print_stack(self):
+	if self.front is None:
+	    print("UNDERFLOW!")
+	else:
+	    temp = self.front
+	    while temp is not None:
+		print(temp.data, end=" <--> ")
+		temp = temp.next
+	    print()
+
+def main():
+    Num = 1
+    numOfBusiness = 0
+    numOfFirst = 0
+    businessSpace = 0
+    firstSpace = 0
+
+    while True:
+	os.system('cls' if os.name == 'nt' else 'clear')
+	print("\t*** MENU *** ")
+	print("1. Add passenger to file")
+	print("2. Read passengers info from file")
+	print("3. Add carriage to file")
+	print("4. Read carriage info from file")
+	print("5. Show linked lists")
+	choice = input("Your choice:")
+
+	if choice == "1":
+	    print("\n------------------------------------------ ")
+	    with open("Passengers", "ab") as out:
+		print("\t*** Add Passenger ***")
+		firstName = input("Enter first name: ")
+		lastName = input("Enter last name: ")
+		ticketType = input("Enter ticket type (Business/First): ")
+		Psg = Passenger()
+		Psg.set_data(firstName, lastName, ticketType)
+		out.write(Psg.__dict__.encode())
+	    input("\nPress Enter to continue...")
+
+	elif choice == "2":
+	    print("\n\t*** Passenger File *** ")
+	    Num = 1
+	    with open("Passengers", "rb") as f:
+		while True:
+		    data = f.read(1024)
+		    if not data:
+			break
+		    else:
+			Psg = Passenger()
+			Psg.__dict__.update(eval(data))
+			print(f"{Num}.")
+			Psg.display()
+			Num += 1
+	    input("\nPress Enter to continue...")
+
+	elif choice == "3":
+	    print("\n------------------------------------------ ")
+	    with open("Carriages", "ab") as out:
+		print("\t*** Add Carriages ***")
+		carriageID = input("Enter ID: ")
+		carriageType = input("Enter type (Business/First): ")
+		carriagePlaces = int(input("Enter number of seats: "))
+		Crg = Carriage()
+		Crg.set_data(carriageType, carriageID, carriagePlaces)
+		out.write(Crg.__dict__.encode())
+	    input("\nPress Enter to continue...")
+
+	elif choice == "4":
+	    print("\n\t*** Carriage File ***")
+	    Num = 1
+	    with open("Carriages", "rb") as f:
+		while True:
+		    data = f.read(1024)
+		    if not data:
+			break
+		    else:
+			Crg = Carriage()
+			Crg.__dict__.update(eval(data))
+			print(f"{Num}.")
+			Crg.display()
+			Num += 1
+	    input("\nPress Enter to continue...")
+
+	elif choice == "5":
+	    listBusiness = LinkedList()
+	    listFirst = LinkedList()
+	    numOfBusiness = 0
+	    numOfFirst = 0
+	    with open("Passengers", "rb") as f:
+		while True:
+		    data = f.read(1024)
+		    if not data:
+			break
+		    else:
+			Psg = Passenger()
+			Psg.__dict__.update(eval(data))
+			if Psg.get_ticket_type() == "Business":
+			    listBusiness.add_node(Num)
+			    numOfBusiness += 1
+			else:
+			    listFirst.add_node(Num)
+			    numOfFirst += 1
+			Num += 1
+	    print("\n------------------------------------------ ")
+	    print("Linked List - 'Business class'")
+	    listBusiness.display()
+	    print("Overall 'Business':", numOfBusiness, "\n")
+	    print("Linked List - 'First class'")
+	    listFirst.display()
+	    print("Overall 'First':", numOfFirst)
+	    print("------------------------------------------ ")
+	    businessSpace = 0
+	    firstSpace = 0
+	    with open("Carriages", "rb") as f:
+		while True:
+		    data = f.read(1024)
+		    if not data:
+			break
+		    else:
+			Crg = Carriage()
+			Crg.__dict__.update(eval(data))
+			if Crg.get_carriage_type() == "Business":
+			    businessSpace += Crg.get_carriage_places()
+			else:
+			    firstSpace += Crg.get_carriage_places()
+			  businessSpace = math.ceil(businessSpace / 2)
+		    firstSpace = math.ceil(firstSpace / 2)
+		    while True:
+			print("\n\t*** INNER MENU *** ")
+			print("1. Distribute 'Business class'")
+			print("2. Distribute 'First class'")
+			print("0. Go back ")
+			inner_choice = input("Your choice:")
+			if inner_choice == "1":
+			    stackBusiness = Stack()
+			    print("\n------------------------------------------ ")
+			    print("Number of free spaces (Business):", businessSpace)
+			    if numOfBusiness <= businessSpace:
+				for i in range(numOfBusiness):
+				    distributedPerson = listBusiness.get_first_element()
+				    stackBusiness.push(distributedPerson)
+				    listBusiness.delete_first()
+				    businessSpace -= 1
+				print("Free spaces left:", businessSpace)
+			    elif numOfBusiness > businessSpace:
+				for i in range(businessSpace):
+				    distributedPerson = listBusiness.get_first_element()
+				    stackBusiness.push(distributedPerson)
+				    listBusiness.delete_first()
+				print("You need", numOfBusiness - businessSpace, "more spaces!")
+			    else:
+				print("You need", numOfBusiness - businessSpace, "free spaces!")
+			    print("Business class passengers list: ", end="")
+			    stackBusiness.print_stack()
+			    input("\nPress Enter to continue...")
+			elif inner_choice == "2":
+			    stackFirst = Stack()
+			    print("\n------------------------------------------ ")
+			    print("Number of free spaces (First):", firstSpace)
+			    if numOfFirst <= firstSpace:
+				for i in range(numOfFirst):
+				    distributedPerson = listFirst.get_first_element()
+				    stackFirst.push(distributedPerson)
+				    listFirst.delete_first()
+				    firstSpace -= 1
+				print("Free spaces left:", firstSpace)
+			    elif numOfFirst > firstSpace:
+				for i in range(firstSpace):
+				    distributedPerson = listFirst.get_first_element()
+				    stackFirst.push(distributedPerson)
+				    listFirst.delete_first()
+				print("You need", numOfFirst - firstSpace, "more spaces!")
+			    else:
+				print("You need", numOfFirst - firstSpace, "spaces!")
+			    print("First class passengers list: ", end="")
+			    stackFirst.print_stack()
+			    input("\nPress Enter to continue...")
+			elif inner_choice == "0":
+			    break
+			else:
+			    print("\nYour choice is not available in the menu!")
+			    input("\nPress Enter to continue...")
+	    else:
+		print("\nYour choice is not available in the menu!")
+		input("\nPress Enter to continue...")
+
+if __name__ == "__main__":
+    main()