java.lang.Object
g0901_1000.s0958_check_completeness_of_a_binary_tree.Solution

public class Solution extends java.lang.Object
958 - Check Completeness of a Binary Tree.

Medium

Given the root of a binary tree, determine if it is a complete binary tree.

In a complete binary tree , every level, except possibly the last, is completely filled, and all nodes in the last level are as far left as possible. It can have between 1 and 2h nodes inclusive at the last level h.

Example 1:

Input: root = [1,2,3,4,5,6]

Output: true

Explanation: Every level before the last is full (ie. levels with node-values {1} and {2, 3}), and all nodes in the last level ({4, 5, 6}) are as far left as possible.

Example 2:

Input: root = [1,2,3,4,5,null,7]

Output: false

Explanation: The node with value 7 isn’t as far left as possible.

Constraints:

  • The number of nodes in the tree is in the range [1, 100].
  • 1 <= Node.val <= 1000
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • isCompleteTree

      public boolean isCompleteTree(TreeNode root)