Iterative_Implementation_link_list.ipynb

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      "authorship_tag": "ABX9TyMry3PW4DWsyyV5Zt01r2YJ",
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    "language_info": {
      "name": "python"
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  "cells": [
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      "cell_type": "markdown",
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        "<a href=\"https://colab.research.google.com/github/SajidMajeed92/Data-Structures-Algorithms-with-Python/blob/main/Iterative_Implementation_link_list.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
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    {
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      "metadata": {
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      "outputs": [],
      "source": [
        "class Node:\n",
        "    def __init__(self, data):\n",
        "        self.data = data\n",
        "        self.next = None\n",
        "\n",
        "\n",
        "class LinkedList:\n",
        "    def __init__(self):\n",
        "        self.head = None\n",
        "\n",
        "    def print_list(self):\n",
        "        cur_node = self.head\n",
        "        while cur_node:\n",
        "            print(cur_node.data)\n",
        "            cur_node = cur_node.next\n",
        "\n",
        "    def append(self, data):\n",
        "        new_node = Node(data)\n",
        "\n",
        "        if self.head is None:\n",
        "            self.head = new_node\n",
        "            return\n",
        "\n",
        "        last_node = self.head\n",
        "        while last_node.next:\n",
        "            last_node = last_node.next\n",
        "        last_node.next = new_node\n",
        "\n",
        "    def prepend(self, data):\n",
        "        new_node = Node(data)\n",
        "\n",
        "        new_node.next = self.head\n",
        "        self.head = new_node\n",
        "\n",
        "    def insert_after_node(self, prev_node, data):\n",
        "\n",
        "        if not prev_node:\n",
        "            print(\"Previous node does not exist.\")\n",
        "            return \n",
        "\n",
        "        new_node = Node(data)\n",
        "\n",
        "        new_node.next = prev_node.next\n",
        "        prev_node.next = new_node\n",
        "\n",
        "    def delete_node(self, key):\n",
        "\n",
        "        cur_node = self.head\n",
        "\n",
        "        if cur_node and cur_node.data == key:\n",
        "            self.head = cur_node.next\n",
        "            cur_node = None\n",
        "            return\n",
        "\n",
        "        prev = None \n",
        "        while cur_node and cur_node.data != key:\n",
        "            prev = cur_node\n",
        "            cur_node = cur_node.next\n",
        "\n",
        "        if cur_node is None:\n",
        "            return \n",
        "\n",
        "        prev.next = cur_node.next\n",
        "        cur_node = None\n",
        "\n",
        "    def delete_node_at_pos(self, pos):\n",
        "\n",
        "        cur_node = self.head\n",
        "\n",
        "        if pos == 0:\n",
        "            self.head = cur_node.next\n",
        "            cur_node = None\n",
        "            return\n",
        "\n",
        "        prev = None\n",
        "        count = 1\n",
        "        while cur_node and count != pos:\n",
        "            prev = cur_node \n",
        "            cur_node = cur_node.next\n",
        "            count += 1\n",
        "\n",
        "        if cur_node is None:\n",
        "            return \n",
        "\n",
        "        prev.next = cur_node.next\n",
        "        cur_node = None\n",
        "\n",
        "    def len_iterative(self):\n",
        "\n",
        "        count = 0\n",
        "        cur_node = self.head\n",
        "\n",
        "        while cur_node:\n",
        "            count += 1\n",
        "            cur_node = cur_node.next\n",
        "        return count\n",
        "\n",
        "\n",
        "llist = LinkedList()\n",
        "llist.append(\"A\")\n",
        "llist.append(\"B\")\n",
        "llist.append(\"C\")\n",
        "llist.append(\"D\")\n",
        "\n",
        "\n",
        "print(llist.len_iterative())"
      ]
    }
  ]
}