Merge pull request #34 from BZAghalarov/py

Solution+ rename + typo

Linked Lists/DesingALinkedList/DesignALinkedList.py

@@ -0,0 +1,69 @@
+"""
+        Leetcode : https://leetcode.com/problems/design-linked-list/
+    Geekforgeeks : https://www.educative.io/edpresso/how-to-create-a-linked-list-in-python
+    This code passed all test cases in Leetcode on 10.01.2020:
+"""
+
+class ListNode:
+    def __init__(self, val):
+        self.val = val
+        self.next = None
+
+
+class MyLinkedList(object):
+    def __init__(self):
+        self.head = None
+        self.size = 0
+
+    def get(self, index):
+        if index < 0 or index >= self.size:
+            return -1
+
+        dummyHead = self.head
+        for i in range(index):
+            dummyHead = dummyHead.next
+        return dummyHead.val
+
+    def addAtHead(self, val):
+        newNode = ListNode(val)
+        newNode.next = self.head
+        self.head = newNode
+        self.size += 1
+
+    def addAtTail(self, val):
+        newNode = ListNode(val)
+
+        curr = self.head
+        while curr.next:
+            curr = curr.next
+        curr.next = newNode
+        self.size += 1
+
+    def addAtIndex(self, index, val):
+        if index > self.size:
+            return
+
+        newNode = ListNode(val)
+        curr = self.head
+        if index <= 0:
+            newNode.next = curr
+            self.head = newNode
+        else:
+            for i in range(index - 1):
+                curr = curr.next
+            newNode.next = curr.next
+            curr.next = newNode
+        self.size += 1
+
+    def deleteAtIndex(self, index):
+        if index < 0 or index >= self.size:
+            return
+
+        curr = self.head
+        if index == 0:
+            self.head = self.head.next
+        else:
+            for i in range(index - 1):
+                curr = curr.next
+            curr.next = curr.next.next
+        self.size -= 1