Python TreeNode.print_in_level_order示例

示例#1

        """
        :type root: TreeNode
        :rtype: List[List[int]]
        """
        if root is None:
            return []
        current_level = [root]
        next_level = []
        result = []
        while current_level:
            level_value_list = []
            for current_node in current_level:
                level_value_list.append(current_node.val)
                next_level.append(
                    current_node.left) if current_node.left else None
                next_level.append(
                    current_node.right) if current_node.right else None
            current_level = next_level
            next_level = []
            result.append(level_value_list)
        return result


if __name__ == '__main__':
    t = TreeNode.build_by_level_order([1, 2, 3, '#', '#', 4, '#', '#', 5])
    print Solution().levelOrder(t)
    TreeNode.print_in_level_order(t)
    t2 = TreeNode.build_by_level_order([3, 9, 20, '#', '#', 15, 7])
    print Solution().levelOrder(t2)
    t3 = TreeNode.build_by_level_order([3])
    print Solution().levelOrder(t3)

示例#2

文件： convert-sorted-array-to-binary-search-tree.py 项目： XericZephyr/LeetCode

class Solution(object):
    def sortedArrayToBST(self, nums):
        """
        :type nums: List[int]
        :rtype: TreeNode
        """
        def op(start, end):
            if start == end:
                return TreeNode(nums[start])
            elif end - start == 1:
                root = TreeNode(nums[start])
                root.right = TreeNode(nums[end])
                return root
            else:
                pivot = (start + end)/2
                root = TreeNode(nums[pivot])
                root.left = op(start, pivot-1)
                root.right = op(pivot+1, end)
                return root
        if len(nums) == 0:
            return None
        return op(0, len(nums)-1)


if __name__ == '__main__':
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1,2,3,4,5]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1,2,3,4,5,6]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1,2]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([]))

示例#3

文件： invert-binary-tree.py 项目： XericZephyr/LeetCode

__author__ = 'clp'

from utils import TreeNode

class Solution(object):

    def invertTree(self, root):
        """
        :type root: TreeNode
        :rtype: TreeNode
        """
        def invert_tree(root):
            if root is None:
                return None
            root.left, root.right = root.right, root.left
            invert_tree(root.left)
            invert_tree(root.right)

        if root:
            invert_tree(root)
        return root

if __name__ == '__main__':
    TreeNode.print_in_level_order(Solution().invertTree(TreeNode.build_by_level_order([4, 2, 7, 1, '#',6,9])))
    TreeNode.print_in_level_order(Solution().invertTree(TreeNode.build_by_level_order([])))

示例#4

文件： convert-sorted-list-to-binary-search-tree.py 项目： XericZephyr/LeetCode

from utils import TreeNode, ListNode

class Solution(object):
    def sortedListToBST(self, head):
        """
        :type head: ListNode
        :rtype: TreeNode
        """
        if head is None:
            return None
        fast, prev, slow = head, None, head
        while fast and fast.next:
            fast = fast.next.next
            prev, slow = slow, slow.next
        root = TreeNode(slow.val)
        if prev:
            prev.next = None
        else:
            return root
        root.left = self.sortedListToBST(head)
        root.right = self.sortedListToBST(slow.next)
        return root


if __name__ == '__main__':
    TreeNode.print_in_level_order(Solution().sortedListToBST(ListNode.build_linked_list([1,2])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(ListNode.build_linked_list([1])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(ListNode.build_linked_list([1,2,3,4,5,6])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(ListNode.build_linked_list([1,2,3,4,5])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(ListNode.build_linked_list([])))

示例#5

文件： convert-sorted-list-to-binary-search-tree.py 项目： XericZephyr/LeetCode

        :type head: ListNode
        :rtype: TreeNode
        """
        if head is None:
            return None
        fast, prev, slow = head, None, head
        while fast and fast.next:
            fast = fast.next.next
            prev, slow = slow, slow.next
        root = TreeNode(slow.val)
        if prev:
            prev.next = None
        else:
            return root
        root.left = self.sortedListToBST(head)
        root.right = self.sortedListToBST(slow.next)
        return root


if __name__ == '__main__':
    TreeNode.print_in_level_order(Solution().sortedListToBST(
        ListNode.build_linked_list([1, 2])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(
        ListNode.build_linked_list([1])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(
        ListNode.build_linked_list([1, 2, 3, 4, 5, 6])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(
        ListNode.build_linked_list([1, 2, 3, 4, 5])))
    TreeNode.print_in_level_order(Solution().sortedListToBST(
        ListNode.build_linked_list([])))

示例#6

文件： binary-tree-level-order-traversal.py 项目： XericZephyr/LeetCode

        """
        :type root: TreeNode
        :rtype: List[List[int]]
        """
        if root is None:
            return []
        current_level = [root]
        next_level = []
        result = []
        while current_level:
            level_value_list = []
            for current_node in current_level:
                level_value_list.append(current_node.val)
                next_level.append(current_node.left) if current_node.left else None
                next_level.append(current_node.right) if current_node.right else None
            current_level = next_level
            next_level = []
            result.append(level_value_list)
        return result




if __name__ == '__main__':
    t = TreeNode.build_by_level_order([1,2,3,'#','#',4,'#','#',5])
    print Solution().levelOrder(t)
    TreeNode.print_in_level_order(t)
    t2 = TreeNode.build_by_level_order([3,9,20,'#','#',15,7])
    print Solution().levelOrder(t2)
    t3 = TreeNode.build_by_level_order([3])
    print Solution().levelOrder(t3)

示例#7

__author__ = 'clp'

from utils import TreeNode


class Solution(object):
    def invertTree(self, root):
        """
        :type root: TreeNode
        :rtype: TreeNode
        """
        def invert_tree(root):
            if root is None:
                return None
            root.left, root.right = root.right, root.left
            invert_tree(root.left)
            invert_tree(root.right)

        if root:
            invert_tree(root)
        return root


if __name__ == '__main__':
    TreeNode.print_in_level_order(Solution().invertTree(
        TreeNode.build_by_level_order([4, 2, 7, 1, '#', 6, 9])))
    TreeNode.print_in_level_order(Solution().invertTree(
        TreeNode.build_by_level_order([])))

示例#8

        """
        :type nums: List[int]
        :rtype: TreeNode
        """
        def op(start, end):
            if start == end:
                return TreeNode(nums[start])
            elif end - start == 1:
                root = TreeNode(nums[start])
                root.right = TreeNode(nums[end])
                return root
            else:
                pivot = (start + end) / 2
                root = TreeNode(nums[pivot])
                root.left = op(start, pivot - 1)
                root.right = op(pivot + 1, end)
                return root

        if len(nums) == 0:
            return None
        return op(0, len(nums) - 1)


if __name__ == '__main__':
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1, 2, 3, 4, 5]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST(
        [1, 2, 3, 4, 5, 6]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1, 2]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([1]))
    TreeNode.print_in_level_order(Solution().sortedArrayToBST([]))