solved: singly linked-list design, improved completion slightly. Taki…

…ng over 3x 15 minutes to complete. Need to review this. -@iamserda

neetcodeio/algostructybeginners/Lv2-LinkedLists/singlyLinkedList3.py

@@ -0,0 +1,83 @@
+class Node:
+    def __init__(self, val: int):
+        self.val = val
+        self.next = None
+
+
+class LinkedList:
+
+    def __init__(self):
+        self.head = None
+        self.tail = None
+        self.length = 0
+
+    def get(self, index: int) -> int:
+        if index >= 0 and index < self.length:
+            temp = self.head
+            counter = 0
+            while temp:
+                if counter == index:
+                    return temp.val
+                temp = temp.next
+                counter += 1
+        return -1
+
+    def insertHead(self, val: int) -> None:
+        new_node = Node(val)
+        if self.length == 0:
+            self.tail = new_node
+            self.head = new_node
+            self.length = 1
+        else:
+            new_node.next = self.head
+            self.head = new_node
+            self.length += 1
+
+    def insertTail(self, val: int) -> None:
+        new_node = Node(val)
+        if not self.head:
+            self.head = new_node
+            self.tail = new_node
+            self.length = 1
+        else:
+            self.tail.next = new_node
+            self.tail = new_node
+            self.length += 1
+
+    def remove(self, index: int) -> bool:
+        if self.head and index < self.length:
+            counter = 0
+            temp = self.head
+            while temp:
+                if counter == 0 and index == counter:
+                    self.head = temp.next
+                    self.length -= 1
+                    temp.next = None
+                    if self.length == 0:
+                        self.tail = None
+                    return True
+                elif counter + 1 == index:
+                    removed = temp.next
+                    if removed:
+                        temp.next = removed.next
+                        removed.next = None
+                        self.length -= 1
+                        if removed == self.tail:
+                            self.tail = temp
+                        return True
+                temp = temp.next
+                counter += 1
+        return False
+
+    def getValues(self) -> List[int]:
+        temp = self.head
+        values = []
+        while temp:
+            values.append(temp.val)
+            temp = temp.next
+        return values
+
+
+singly = LinkedList()
+singly.insertHead(1)
+print(singly.getValues())