solved invert Binary tree

Author: jasmeet0502

0ne.ipynb

@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 71,
+   "execution_count": 39,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -11,33 +11,62 @@
     "        self.val = val\n",
     "        self.next = next\n",
     "\n",
-    "\n",
     "a = ListNode(-1, ListNode(2, ListNode(8)))\n",
-    "b = ListNode(3, ListNode(4, ListNode(7)))"
+    "b = ListNode(-3, ListNode(4, ListNode(7)))"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 84,
+   "execution_count": 40,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "('a', 1)\n",
-      "('b', 2)\n"
+      "[-3, -1, 2, 4, 7, 8]\n"
      ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "<__main__.ListNode at 0x1887c6f4b80>"
+      ]
+     },
+     "execution_count": 40,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": [
-    "a  = {\n",
-    "    'a': 1,\n",
-    "    'b': 2\n",
-    "}\n",
-    "\n",
-    "for node in a.items():\n",
-    "    print(node)"
+    "class Solution:\n",
+    "    def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:\n",
+    "        dummy = ListNode()\n",
+    "        tail = dummy\n",
+    "        \n",
+    "        while l1 and l2:\n",
+    "            if l1.val < l2.val:\n",
+    "                tail.next = l1\n",
+    "                l1 = l1.next\n",
+    "            else:\n",
+    "                tail.next = l2\n",
+    "                l2 = l2.next\n",
+    "            tail = tail.next\n",
+    "        \n",
+    "        if l1:\n",
+    "            tail.next = l1\n",
+    "        elif l2:\n",
+    "            tail.next = l2\n",
+    "        \n",
+    "        arr = []\n",
+    "        node = dummy.next\n",
+    "        while node:\n",
+    "            arr.append(node.val)\n",
+    "            node = node.next\n",
+    "        print(arr)\n",
+    "        return dummy.next\n",
+    "                \n",
+    "Solution.mergeTwoLists(0, a,b)"
    ]
   }
  ],

21-Merge-Two-Sorted-Lists.py

@@ -0,0 +1,32 @@
+class ListNode:
+    def __init__(self, val=0, next=None) -> None:
+        self.val = val
+        self.next = next
+
+a = ListNode(-1, ListNode(2, ListNode(8)))
+b = ListNode(-3, ListNode(4, ListNode(7)))
+
+from typing import Optional
+
+class Solution:
+    def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) -> Optional[ListNode]:
+        dummy = ListNode()
+        tail = dummy
+        
+        while list1 and list2:
+            if list2.val > list1.val:
+                tail.next = list1
+                list1 = list1.next
+                tail = tail.next
+            else:
+                tail.next = list2
+                list2 = list2.next
+                tail = tail.next
+                
+        if list1:
+            tail.next = list1
+        elif list2:
+            tail.next = list2
+            
+        return dummy.next
+                

226-Invert-Binary-Tree.py

@@ -0,0 +1,18 @@
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+from typing import Optional
+
+class Solution:
+    def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
+        if root is None: return None
+        
+        root.left, root.right = root.right, root.left
+        
+        self.invertTree(root.right)
+        self.invertTree(root.left)
+        
+        return root