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3 years ago

Linked List

Table Of Contents

Use Case 1: Phone Directory

Phone directory: Problem statement

Let’s create a phone directory using Linked list.

Details in a node are name and phone number.

We need to insert the nodes in the linked list in a sorted order by the name.

# Create a Node to store the contact

class Contact:
    def __init__(self, name, number, nextContact=None):
        self.name = name
        self.number = number
        self.nextContact = nextContact
        #print("Constructor called")
        #print("Name, Number, NextPointer: ",self.name," | ",self.number," | ",self.nextContact)

# Create a class PhoneDirectory: add_contact(), display_phone_directory()
class PhoneDirectory:
    def __init__(self):
        self.root = None
        print("Phone Directory constructor called. Root= ",self.root)
        
    def add_contact(self, contact):
        if self.root is None:
            self.root = contact
            print("self.root.name: ",self.root.name)
            print("self.root.number: ",self.root.number)
            print("self.root.nextContact: ",self.root.nextContact)
            # print(contact)
        
        elif self.root.name > contact.name:
            contact.nextContact = self.root
            self.root = contact
            
        else:
            current = self.root
            while current.name < contact.name and current.nextContact is not None:
                current = current.nextContact
                
            contact.nextContact = current.nextContact
            current.nextContact = contact
            
        def display_phone_directory(self):
            
        
phone_directory = PhoneDirectory()
phone_directory.add_contact(Contact("abc",121))
phone_directory.add_contact(Contact("adc",122))
Phone Directory constructor called. Root= None self.root.name: abc self.root.number: 121 self.root.nextContact: None 
l = [ 10,20,30,40 ]
print(id(l))
for i in l:
    print(id(i))

print("==========================")
l.insert(2,50)
print(l)
print(id(l))
for i in l:
    print(id(i))
1766448563904 140722308786240 140722308786560 140722308786880 140722308787200 ========================== [10, 20, 50, 30, 40] 1766448563904 140722308786240 140722308786560 140722308787520 140722308786880 140722308787200