def recursive(self, l, r) -> TreeNode:
m = (l + r) // 2
root = TreeNode(self.nums[m])
if m > l:
root.left = self.recursive(l, m)
if m < r - 1:
root.right = self.recursive(m + 1, r)
return root
def insertIntoBST(self, root: TreeNode, val: int) -> TreeNode:
if not root:
return TreeNode(val)
if root.val > val:
root.left = self.insertIntoBST(root.left, val)
else:
root.right = self.insertIntoBST(root.right, val)
return root
def recursive(self, preorder: List[int], inorder: List[int]) -> TreeNode:
v = preorder[0]
i = inorder.index(v)
root = TreeNode(v)
if i > 0:
root.left = self.recursive(preorder[1:(1 + i)], inorder[:i])
if i < len(inorder) - 1:
root.right = self.recursive(preorder[(i + 1):], inorder[(i + 1):])
return root
def recursive(self, x):
n = len(x)
i = n // 2
node = TreeNode(x[i])
if n > 1:
node.left = self.recursive(x[:i])
if n > 2:
node.right = self.recursive(x[(i + 1):])
return node
def insertIntoMaxTree(self, root: TreeNode, val: int) -> TreeNode:
# Q0654.
if not root or root.val < val:
node = TreeNode(val)
node.left = root
return node
else:
root.right = self.insertIntoMaxTree(root.right, val)
return root
def constructFromPrePost(self, pre: List[int],
post: List[int]) -> TreeNode:
if not pre:
return None
root = TreeNode(pre[0])
if len(pre) == 1:
return root
i = post.index(pre[1]) + 1
root.left = self.constructFromPrePost(pre[1:(i + 1)], post[:i])
root.right = self.constructFromPrePost(pre[i + 1:], post[i:-1])
return root
def recursive(self, pre, post):
node = TreeNode(pre[0])
# i is the index on post matches pre[1]
# pre[1] is the root of the left subtree
i = len(post) - 2
while i > -1 and not pre[1] == post[i]:
i -= 1
if i >= 0:
node.left = self.recursive(pre[1:(i + 2)], post[:(i + 1)])
if i < len(post) - 2:
node.right = self.recursive(pre[(i + 2):], post[(i + 1):-1])
return node
def mergeTrees(self, t1: TreeNode, t2: TreeNode) -> TreeNode:
if t1 and t2:
t = TreeNode(t1.val + t2.val)
t.left = self.mergeTrees(t1.left, t2.left)
t.right = self.mergeTrees(t1.right, t2.right)
elif t1:
t = t1
elif t2:
t = t2
else:
t = None
return t
def recursive(self, l, r) -> TreeNode:
"""Args:
l, r: sub-inorder formed from self.inorder[l:r], l < r
"""
v = self.preorder[self.preindex]
i = self.inorder[v]
self.preindex += 1
root = TreeNode(v)
if i > l:
root.left = self.recursive(l, i)
if i < r - 1:
root.right = self.recursive(i + 1, r)
return root
def allPossibleFBT(self, N: int) -> List[TreeNode]:
if N & 1:
if N not in self.memo:
self.memo[N] = []
for i in range(1, N, 2):
for x in self.allPossibleFBT(i):
for y in self.allPossibleFBT(N - 1 - i):
node = TreeNode(0)
node.left = x
node.right = y
self.memo[N].append(node)
return self.memo[N]
return []
def subtreeWithAllDeepest(self, root: TreeNode) -> TreeNode:
# preorder traversal, assign depth
root.depth = 0
stack, dmax, dmaxNodes = [root], 0, {root}
while stack:
node = stack.pop()
if node.right:
node.right.parent = node
node.right.depth = node.depth + 1
if node.right.depth > dmax:
dmax = node.right.depth
dmaxNodes = {node.right}
elif node.right.depth == dmax:
dmaxNodes.add(node.right)
stack.append(node.right)
if node.left:
node.left.parent = node
node.left.depth = node.depth + 1
if node.left.depth > dmax:
dmax = node.left.depth
dmaxNodes = {node.left}
elif node.left.depth == dmax:
dmaxNodes.add(node.left)
stack.append(node.left)
# climb back to common ancestor
while len(dmaxNodes) > 1:
dmaxNodes = set(node.parent for node in dmaxNodes)
return dmaxNodes.pop()
def bstFromPreorder(self, preorder: List[int]) -> TreeNode:
n = len(preorder)
if not n:
return None
root = TreeNode(preorder[0])
stack = [root]
for i in range(1, n):
node, child = stack[-1], TreeNode(preorder[i])
while stack and stack[-1].val < child.val:
node = stack.pop()
if node.val > child.val:
node.left = child
else:
node.right = child
stack.append(child)
return root
def flipMatchVoyage(self, root: TreeNode, voyage: List[int]) -> List[int]:
if root and voyage:
if root.val == voyage[0]:
if root.left and root.right:
X = []
if root.left.val == voyage[1]:
pass
elif root.right.val == voyage[1]:
root.left, root.right = root.right, root.left
X = [root.val]
else:
return [-1]
try:
i = voyage.index(root.right.val)
L = self.flipMatchVoyage(root.left, voyage[1:i])
if L == [-1]:
return [-1]
R = self.flipMatchVoyage(root.right, voyage[i:])
if R == [-1]:
return [-1]
return X + L + R
except ValueError as identifier:
return [-1]
elif root.left:
return self.flipMatchVoyage(root.left, voyage[1:])
elif root.right:
return self.flipMatchVoyage(root.right, voyage[1:])
else:
return []
else:
return [-1]
def minCameraCover(self, root: TreeNode) -> int:
self.count = 0
self.recursive(root)
if root.val == root.mnt == 0:
root.val = 1
self.count += 1
return self.count
def splitBST(self, root: TreeNode, V: int) -> List[TreeNode]:
if not root:
return None, None
elif root.val > V:
node, root.left = self.splitBST(root.left, V)
return node, root
else:
root.right, node = self.splitBST(root.right, V)
return root, node
def recursive(self, i):
if i == self.n:
return None, self.n
v = ""
while i < self.n and not (self.s[i] == "(" or self.s[i] == ")"):
v += self.s[i]
i += 1
node = TreeNode(int(v))
if i < self.n and self.s[i] == "(":
node.left, i = self.recursive(i + 1)
if i < self.n and self.s[i] == "(":
node.right, i = self.recursive(i + 1)
if i < self.n and self.s[i] == ")":
i += 1
elif i < self.n and self.s[i] == ")":
i += 1
elif i < self.n and self.s[i] == ")":
i += 1
return node, i
def deserialize(self, data: str) -> TreeNode:
"""Decodes your encoded data to tree.
"""
x = deque([int(v) for v in data.split()])
if not x:
return None
root = TreeNode(x.popleft())
# decode w.r.t bst property
stack = [root]
while x:
node = TreeNode(x.popleft())
if node.val < stack[-1].val:
stack[-1].left = node
else:
while stack and node.val > stack[-1].val:
hold = stack.pop()
hold.right = node
stack.append(node)
return root
def deserialize(self, data: str) -> TreeNode:
"""Decodes your encoded data to tree.
"""
x = deque(data.split(','))
v = x.popleft()
if v == "" or v == " ":
return None
root = TreeNode(v)
stack = deque([root, ])
while x:
node = stack.popleft()
v = x.popleft()
if not v == " ":
node.left = TreeNode(v)
stack.append(node.left)
if x:
v = x.popleft()
if not v == " ":
node.right = TreeNode(v)
stack.append(node.right)
return root
def preorderListToTreeNode(self, x: List) -> TreeNode:
"""preorder representation of tree as list with none back to root (TreeNode), copied from ./config/treenode.py
"""
if not x:
return None
root = TreeNode(x[0])
i, q = 1, [
[root, True],
]
while i < len(x):
node, ld = q[-1]
item = x[i]
if ld:
q[-1][1] = False
if item is not None:
node.left = TreeNode(item)
q.append([node.left, True])
else:
q.pop()
if item is not None:
node.right = TreeNode(item)
q.append([node.right, True])
i += 1
return root
def insert(self, v: int) -> int:
# create and connect
node = TreeNode(v)
if self.q[0][0]:
self.q[0][1].right = node
else:
self.q[0][1].left = node
x = self.q[0][1].val
# pop if complete
self.q[0][0] += 1
if self.q[0][0] == 2:
self.q.popleft()
# append new node
self.q.append([0, node])
return x
def recoverFromPreorder(self, S: str) -> TreeNode:
stack, i = [], 0
while i < len(S):
d, x = 0, ''
while i < len(S) and S[i] == '-':
d += 1
i += 1
while i < len(S) and S[i] != '-':
x += S[i]
i += 1
while len(stack) > d:
stack.pop()
node = TreeNode(x)
if stack and stack[-1].left is None:
stack[-1].left = node
elif stack:
stack[-1].right = node
stack.append(node)
return stack[0]
def simulateInorderTraversal(self, l, r) -> TreeNode:
if l == r - 1:
node = TreeNode(self.head.val)
self.head = self.head.next
return node
m = (l + r) // 2
if m > l:
hold = self.simulateInorderTraversal(l, m)
node = TreeNode(self.head.val)
self.head = self.head.next
node.left = hold
if m < r - 1:
node.right = self.simulateInorderTraversal(m + 1, r)
return node
def treeToDoublyList(self, root: TreeNode) -> TreeNode:
# sentinel
s = TreeNode('')
# inorder traversal
x = s
if root:
node, stack = root, []
while node or stack:
while node:
stack.append(node)
node = node.left
# next smallest
node = stack.pop()
# create the double link in-place
x.right = node
node.left = x
# move along the path of double linked list
x = node
# move along the path of tree inorder traversal
node = node.right
# complete the circle
x.right = s.right
s.right.left = x
return s.right
# if __name__ == '__main__':
# solver = Solution()
# cases = [
# [],
# [1],
# [2,1,3],
# [4,2,5,1,3],
# ]
# cases = [
# listToTreeNode(x) for x in cases
# ]
# rslts = [
# solver.treeToDoublyList(root) for root in cases
# ]
# for cs, rs in zip(cases, rslts):
# print(f"case:\n{cs.display() if cs else None} | solution: {rs}")
def addOneRow(self, root: TreeNode, v: int, d: int) -> TreeNode:
if d == 1:
node = TreeNode(v)
node.left = root
return node
# level order traversal
if root:
level, stack = 0, [root]
while stack:
level, queue = level + 1, []
if level == d - 1:
for node in stack:
xl, xr = TreeNode(v), TreeNode(v)
xl.left, xr.right = node.left, node.right
node.left, node.right = xl, xr
break
else:
for node in stack:
if node.left:
queue.append(node.left)
if node.right:
queue.append(node.right)
stack = queue
return root
def deleteNode(self, root: TreeNode, key: int) -> TreeNode:
if not root:
return None
if root.val > key:
root.left = self.deleteNode(root.left, key)
elif root.val < key:
root.right = self.deleteNode(root.right, key)
else:
if root.left:
root.val = self.predcessor(root)
root.left = self.deleteNode(root.left, root.val)
elif root.right:
root.val = self.successor(root)
root.right = self.deleteNode(root.right, root.val)
else:
root = None
return root
def recoverFromPreorder(self, S: str) -> TreeNode:
stack, i, n, d, x = [], 0, len(S), 0, ''
while i < n:
while S[i] == '-':
d += 1
i += 1
while i < n and S[i].isdigit():
x += S[i]
i += 1
node = TreeNode(int(x))
if d == 0:
root = node
stack.append((d, node))
else:
while stack and stack[-1][0] >= d:
stack.pop()
if not stack[-1][1].left:
stack[-1][1].left = node
else:
stack[-1][1].right = node
stack.pop()
stack.append((d, node))
d, x = 0, ''
return root
def __init__(self):
self.memo = {}
self.memo[1] = [TreeNode(0)]