added problems

AlveeM · AlveeM · commit d2d12bf969ad · 2021-03-23T09:43:12.000-04:00
diff --git a/leetcode/top-interview-questions/02_medium_collection/02_linked_list/01_add_two_numbers.py b/leetcode/top-interview-questions/02_medium_collection/02_linked_list/01_add_two_numbers.py
@@ -0,0 +1,20 @@
+class Solution:
+    def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
+        head = ListNode(0)
+        cur = head
+        carry = 0
+        
+        while any([l1, l2, carry]):
+            v1 = l1.val if l1 else 0
+            v2 = l2.val if l2 else 0
+            total = v1 + v2 + carry
+            
+            carry, res = divmod(total, 10)
+            
+            cur.next = ListNode(res)
+            cur = cur.next
+            
+            l1 = l1.next if l1 else None
+            l2 = l2.next if l2 else None
+        
+        return head.next
diff --git a/leetcode/top-interview-questions/02_medium_collection/02_linked_list/02_odd_even_linked_list.py b/leetcode/top-interview-questions/02_medium_collection/02_linked_list/02_odd_even_linked_list.py
@@ -0,0 +1,20 @@
+class Solution:
+    def oddEvenList(self, head: ListNode) -> ListNode:
+        if not head or not head.next: return head
+
+        odd_head = head
+        even_head = head.next
+        odd = odd_head
+        even = even_head
+
+        while even:
+            if even.next:
+                odd.next = even.next
+            else:
+                odd.next = even_head
+                return odd_head
+            odd = odd.next
+            even.next = odd.next
+            even = even.next
+        
+        return odd_head
diff --git a/leetcode/top-interview-questions/02_medium_collection/02_linked_list/03_intersection_of_two_linked_lists.py b/leetcode/top-interview-questions/02_medium_collection/02_linked_list/03_intersection_of_two_linked_lists.py
@@ -0,0 +1,10 @@
+class Solution:
+    def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> ListNode:
+        p1 = headA
+        p2 = headB
+        
+        while p1 != p2:
+            p1 = headB if p1 is None else p1.next
+            p2 = headA if p2 is None else p2.next
+        
+        return p1
diff --git a/leetcode/top-interview-questions/02_medium_collection/03_trees_and_graphs/01_binary_tree_inorder_traversal.py b/leetcode/top-interview-questions/02_medium_collection/03_trees_and_graphs/01_binary_tree_inorder_traversal.py
@@ -0,0 +1,14 @@
+class Solution:
+    def inorderTraversal(self, root: TreeNode) -> List[int]:
+        res = []
+        stack = []
+        
+        while True:
+            while root:
+                stack.append(root)
+                root = root.left
+            if not stack:
+                return res
+            node = stack.pop()
+            res.append(node.val)
+            root = node.right
diff --git a/leetcode/top-interview-questions/02_medium_collection/03_trees_and_graphs/02_binary_tree_zigzag_level_order_traversal.py b/leetcode/top-interview-questions/02_medium_collection/03_trees_and_graphs/02_binary_tree_zigzag_level_order_traversal.py
@@ -0,0 +1,29 @@
+from collections import deque
+
+class Solution:
+    def zigzagLevelOrder(self, root: TreeNode) -> List[List[int]]:
+        if not root: return root
+        
+        q = deque()
+        q.append(root)
+        l_to_r = True
+        res = []
+        
+        while q:
+            n = len(q)
+            level = deque()
+            for _ in range(n):
+                node = q.popleft()
+                if l_to_r:
+                    level.append(node.val)
+                else:
+                    level.appendleft(node.val)
+                
+                if node.left:
+                    q.append(node.left)
+                if node.right:
+                    q.append(node.right)
+            res.append(level)
+            l_to_r = not l_to_r
+            
+        return res
