Package g0901_1000.s0958_check_completeness_of_a_binary_tree

Class Solution

java.lang.Object
g0901_1000.s0958_check_completeness_of_a_binary_tree.Solution
public class Solution extends Object
958 - Check Completeness of a Binary Tree.<p>Medium</p> <p>Given the <code>root</code> of a binary tree, determine if it is a <em>complete binary tree</em>.</p> <p>In a <strong><a href="http://en.wikipedia.org/wiki/Binary_tree#Types_of_binary_trees" target="_top">complete binary tree</a></strong> , 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 <code>1</code> and <code>2<sup>h</sup></code> nodes inclusive at the last level <code>h</code>.</p> <p><strong>Example 1:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2018/12/15/complete-binary-tree-1.png" alt="" /></p> <p><strong>Input:</strong> root = [1,2,3,4,5,6]</p> <p><strong>Output:</strong> true</p> <p><strong>Explanation:</strong> 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.</p> <p><strong>Example 2:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2018/12/15/complete-binary-tree-2.png" alt="" /></p> <p><strong>Input:</strong> root = [1,2,3,4,5,null,7]</p> <p><strong>Output:</strong> false</p> <p><strong>Explanation:</strong> The node with value 7 isn&rsquo;t as far left as possible.</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the tree is in the range <code>[1, 100]</code>.</li> <li><code>1 <= Node.val <= 1000</code></li> </ul>

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • isCompleteTree

      public boolean isCompleteTree(TreeNode root)