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Two Trees

100. Same Tree​

100. Same Tree

Easy2 solutionsexplanationanalysis2 playgrounds

Explanation

Solutions:

Interactive Visualization

Analysis

def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
def dfs(a, b):
if not a and not b:
return True
if not a or not b:
return False
if a.val != b.val:
return False
return dfs(a.left, b.left) and dfs(a.right, b.right)
 
return dfs(p, q)

101. Symmetric Tree​

101. Symmetric Tree

Easy2 solutionsexplanationanalysis2 playgrounds

Explanation

Solutions:

Interactive Visualization

Analysis

def isSymmetric(self, root: Optional[TreeNode]) -> bool:
def dfs(left, right):
if not right and not left:
return True
if not right or not left:
return False
if left.val != right.val:
return False
return dfs(left.left, right.right) and dfs(left.right, right.left)
 
return dfs(root, root)

1379. Find a Corresponding Node of a Binary Tree in a Clone of That Tree​

Easy3 solutionsexplanationanalysis1 playground

Explanation

Solutions:

Analysis

def getTargetCopy(
self, original: TreeNode, cloned: TreeNode, target: TreeNode
) -> TreeNode:
def dfs(a, b):
if a and b:
if a == target:
return b
left_result = dfs(a.left, b.left)
right_result = dfs(a.right, b.right)
return left_result or right_result
 
return dfs(original, cloned)