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+# 0100. Same Tree
+
+* Difficulty: easy
+* Link: https://leetcode.com/problems/same-tree/
+* Topics: DFS-BFS
+
+# Clarification
+
+1. Check the inputs and outputs
+    - INPUT:
+        - Optional[TreeNode]
+        - Optional[TreeNode]
+    - OUTPUT:
+        - boolean
+
+# Solution
+
+### Thought Process
+
+1. 
+- Implement
+    
+    ```python
+    # Definition for a binary tree node.
+    # class TreeNode:
+    #     def __init__(self, val=0, left=None, right=None):
+    #         self.val = val
+    #         self.left = left
+    #         self.right = right
+    class Solution:
+        def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
+            def isSame(p,q):
+                if not p and not q:
+                    return True
+                if not p or not q:
+                    return False
+                if p.val != q.val:
+                    return False
+                return True
+            
+            deq_p = collections.deque()
+            deq_q = collections.deque()
+            
+            deq_p.append(p)
+            deq_q.append(q)
+            
+            while deq_p and deq_q:
+                p = deq_p.popleft()
+                q = deq_q.popleft()
+                
+                if not isSame(p, q):
+                    return False
+                
+                if p or q:
+                    deq_p.append(p.left)
+                    deq_p.append(p.right)
+                    deq_q.append(q.left)
+                    deq_q.append(q.right)
+        
+            return True
+    ```
+    
+
+### Complexity
+
+- Time complexity: O(n)
+- Space complexity: O(n)
+    - to keep a queue
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