Append value to a new link list

Question

My Aim is to do following

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8

For doing this operation I am first creating a linklist, adding values to the created linklist. And using another function to add these two link lists. However I am getting stuck at the function add two nodes.

Code

class node:
    def __init__(self, data=None):
        self.data = data
        self.next = None


class linklist:
    def __init__(self):
        self.head = node()

    def append(self, data):
        current_node = self.head
        new_node = node(data)
        while current_node.next != None:
            current_node = current_node.next
        current_node.next = new_node

    def display(self):
        elems = []
        current_node = self.head
        while current_node.next != None:
            current_node = current_node.next
            elems.append(current_node.data)
        print(elems)

    def getnode(self, index):
        index_count = 0
        current_node = self.head
        while current_node.next != None:
            current_node = current_node.next
            if index_count == index:
                return current_node.data
            index_count += 1


class adding_lists:

    def add_two_numbers(self, l1, l2, c=0):
        for i in range(3):
            value = l1.getnode(i)+l2.getnode(i)

            print(value)
            '''
            whatever result comes inside value should be added to a new linklist
            '''

        # return new_node


l1 = linklist()
l1.append(2)
l1.append(4)
l1.append(3)
# l1.display()

l2 = linklist()
l2.append(5)
l2.append(6)
l2.append(4)
# l2.display()

add_object = adding_lists()
value = add_object.add_two_numbers(l1, l2)

I am getting stuck on class adding_lists, how do I add value to a new linked-list from within this adding_lists class

How should I append '''value''' generated in the add_two_numbers function (of adding_lists class) to form a completely new linklist data structure ?

Answer 1

You can try:

class node:
    def __init__(self, data=None):
        self.data = data
        self.next = None


class linklist:
    def __init__(self):
        self.head = node()

    def append(self, data):
        current_node = self.head
        new_node = node(data)
        while current_node.next != None:
            current_node = current_node.next
        current_node.next = new_node

    def display(self):
        elems = []
        current_node = self.head
        while current_node.next != None:
            current_node = current_node.next
            elems.append(current_node.data)
        print(elems)

    def getnode(self, index):
        index_count = 0
        current_node = self.head
        while current_node.next != None:
            current_node = current_node.next
            if index_count == index:
                return current_node.data
            index_count += 1


class adding_lists:

    def add_two_numbers(self, l1, l2, c=0):
        output = linklist()
        x = l1.head.next
        y = l2.head.next
        carry = 0
        while x is not None:            
            result = list(str(x.data + y.data + carry))
            carry = int(result[0]) if len(result) > 1 else 0
            output.append(int(result[-1]))
            x = x.next
            y = y.next
        return output

l1 = linklist()
l1.append(2)
l1.append(4)
l1.append(3)
l1.display()

l2 = linklist()
l2.append(5)
l2.append(6)
l2.append(4)
l2.display()

add_object = adding_lists()
result = add_object.add_two_numbers(l1, l2)
result.display()

Answer 2

I think this will work

def add_two_numbers(self, l1, l2, c=0):
    value = linklist()
    for i in range(3):
        subTotal = l1.getnode(i) + l2.getnode(i) + c
        c = 0
        while subTotal > 9:
            subTotal -= 10
            c += 1
        value.append(subTotal)

        # print(value)
        '''
        whatever result comes inside value should be added to a new linklist
        '''

    return value

Then you just need to display the value with value.display().

In my machine i got this, output