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Author: Chris Wu

problems/same-tree.py

@@ -0,0 +1,23 @@
+from collections import deque
+
+class Solution(object):
+    def isSameTree(self, p, q):
+        q1 = deque([p])
+        q2 = deque([q])
+        while q1 or q2:
+            if not q1 or not q2: return False
+            n1 = q1.popleft()
+            n2 = q2.popleft()
+            
+            if n1 and n2:
+                if n1.val!=n2.val: return False
+                q1.append(n1.left)
+                q1.append(n1.right)
+                q2.append(n2.left)
+                q2.append(n2.right)
+            elif n1 and not n2:
+                return False
+            elif not n1 and n2:
+                return False
+        return True
+

problems/symmetric-tree.py

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+from collections import deque
+
+class Solution(object):
+    def isSymmetric(self, root):
+        if not root: return True
+        
+        q = deque()
+        q.append((root.left, root.right))
+        while q:
+            left_node, right_node = q.popleft()
+            if not left_node and right_node: return False
+            if not right_node and left_node: return False
+            
+            if left_node and right_node:
+                if left_node.val!=right_node.val: return False
+                q.append((left_node.right, right_node.left))
+                q.append((left_node.left, right_node.right))
+        return True