Leetcode Algorithms

100. Same Tree

Easy

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Given two binary trees, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical and the nodes have the same value.

Example 1:

Input:     1         1
          / \       / \
         2   3     2   3
        [1,2,3],   [1,2,3]
Output: true

Example 2:

Input:     1         1
          /           \
         2             2
        [1,2],     [1,null,2]
Output: false

Example 3:

Input:     1         1
          / \       / \
         2   1     1   2
        [1,2,1],   [1,1,2]
Output: false

Solution:

# 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: TreeNode, q: TreeNode) -> bool:
        if p == None and q == None:
            return True
        elif p == None and q != None:
            return False
        elif p != None and q == None:
            return False
        elif p.val != q.val:
            return False
        else:
            return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

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