Group_A_1.txt

class HashTable:
    def __init__(self, size):
        self.size = size
        self.table = [None] * size

    def _hash_function(self, key):
        return key % self.size

    def _get_next_index(self, index, i):
        return (index + i) % self.size

    def insert(self, key, value):
        index = self._hash_function(key)
        if self.table[index] is None:
            self.table[index] = (key, value)
        else:
            i = 1
            next_index = self._get_next_index(index, i)
            while self.table[next_index] is not None:
                i += 1
                next_index = self._get_next_index(index, i)
            self.table[next_index] = (key, value)

    def search_by_name(self, name):
        comparisons = 0
        for item in self.table:
            comparisons += 1
            if item is not None and item[1] == name:
                return item[0], comparisons
        return None, comparisons

    def show_list(self):
        print("\n")
        for item in self.table:
            if item is not None:
                print(f"Name: {item[1]}, Telephone number: {item[0]}")
    

def insert_client():
    key = int(input("\nEnter the telephone number: "))
    value = input("Enter the name: ")
    telephone_book.insert(key, value)
    print("\nClient inserted.")


def search_by_name():
    name = input("\nEnter the name to search: ")
    number, comparisons = telephone_book.search_by_name(name)
    if number is not None:
        print(f"\nTelephone number: {number}")
        print(f"Comparisons required: {comparisons}")
    else:
        print("\nClient not found.")
        print(f"Comparisons required: {comparisons}")


def show_list():
    telephone_book.show_list()


size = int(input("Enter the size of the hash table: "))
telephone_book = HashTable(size)

while True:
    print("\n*** MENU ***")
    print("1. Insert client")
    print("2. Search by name")
    print("3. Show list")
    print("4. Exit")
    choice = input("\nEnter your choice: ")

    if choice == "1":
        insert_client()
    elif choice == "2":
        search_by_name()
    elif choice == "3":
        show_list()
    elif choice == "4":
        break
    else:
        print("Invalid choice. Please try again.")