# STEP__2. now using for loop traverse the preorder array remaining elements from index 1'st not 0'th
# now for every element(value) there will be two cases,
# 1. if it is smaller then stack top,
# then it will be left child of stack top ,and insert it value into stack
# 2. if it is greater then stack top,
# then get the next greater element(last) ,and make value its right child and append it to stack
# STEP__3. At last return root
def constructTree(preorderArray):
stack = []
root = BST.BinaryTreeNode(preorderArray[0])
stack.append(root)
for value in preorderArray[1:]:
if value < stack[-1].data:
new_left_node = BST.BinaryTreeNode(value)
stack[-1].left = new_left_node
stack.append(new_left_node)
else:
while stack and stack[-1].data < value:
last = stack.pop()
last.right = BST.BinaryTreeNode(value)
stack.append(last.right)
return root
preorder = [int(i) for i in input().strip().split()]
bstRoot = constructTree(preorder)
BST.PrintLevelWise(bstRoot)
arr.append(arr2[j])
j = j + 1
return arr
# STEP 3:____________________________________________________________
def sortedArrayToBST(arr):
if not arr:
return None
mid = len(arr) // 2
root = BinaryTreeNode(arr[mid])
root.left = sortedArrayToBST(arr[:mid])
root.right = sortedArrayToBST(arr[mid + 1:])
return root
root1 = BST.buildLevelTree()
root2 = BST.buildLevelTree()
arr1 = []
createSortedArray_from_BST(root1, arr1)
arr2 = []
createSortedArray_from_BST(root2, arr2)
arr = mergeSortedArray(arr1, arr2)
root = sortedArrayToBST(arr)
BST.PrintLevelWise(root)
global prev
def flattenBSTHelper(curr):
global prev
if curr is None:
return
flattenBSTHelper(curr.left)
prev.left = None
prev.right = curr
prev = curr
flattenBSTHelper(curr.right)
def flattenBST(root):
global prev
if root is None:
return
dummy = BST.BinaryTreeNode(-1)
prev = dummy
flattenBSTHelper(root)
prev.left = None
prev.right = None
ret = dummy.right
return ret
root = BST.buildLevelTree()
newRoot = flattenBST(root)
BST.PrintLevelWise(newRoot)
