Snippets Collections
class Tree(object):
    def __init__(self, value, left=None, right=None):
        self.val = value
        self.left = left
        self.right = right 
 
tx = Tree(4, Tree(1, Tree(-2, None, Tree(3, None, None))), Tree(3, Tree(1, None, None), Tree(2, Tree(-4, None, None), Tree(-3, None, None))))


def find_paths(root, required_sum):
    allPaths = []
  
    def find_paths_recursive(currentNode, required_sum, currentPath, allPaths):
      if currentNode is None:
        return
    
      # add the current node to the path
      currentPath.append(currentNode.val)
    
      # if the current node is a leaf and its value is equal to required_sum, save the current path
      if currentNode.val == required_sum and currentNode.left is None and currentNode.right is None:
        allPaths.append(list(currentPath))
      else:
        # traverse the left sub-tree
        find_paths_recursive(currentNode.left, required_sum -
                             currentNode.val, currentPath, allPaths)
        # traverse the right sub-tree
        find_paths_recursive(currentNode.right, required_sum -
                             currentNode.val, currentPath, allPaths)
    
      # remove the current node from the path to backtrack,
      # we need to remove the current node while we are going up the recursive call stack.
      del currentPath[-1]
    
    find_paths_recursive(root, required_sum, [], allPaths)
    
    return allPaths

find_paths(tx, 5)
# 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 isSubtree(self, root: Optional[TreeNode], subRoot: Optional[TreeNode]) -> bool:
        #order of first two conditionals is important 
        if not subRoot: return True 
        if not root: return False 
        if self.sameTree(root, subRoot): return True 
        
        return self.isSubtree(root.left, subRoot) or self.isSubtree(root.right, subRoot)
        
        
    def sameTree(self, s, t): 
        if not s and not t: return True 
        if s and t and s.val == t.val: 
            return self.sameTree(s.left, t.left) and self.sameTree(s.right, t.right) 

        return False 
        
        
# 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:
        if not p and not q: return True 
        if not p or not q: return False 
        if p.val != q.val: return False 
        
        return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)
        

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