Balanced Binary Tree
40% Accepted
Given a binary tree, determine if it is height-balanced.
For this problem, a height-balanced binary tree is defined as a binary tree
in which the depth of the two subtrees of every node never differ by more than 1.
Have you met this question in a real interview? Yes
Example
Given binary tree A={3,9,20,#,#,15,7}, B={3,#,20,15,7}
A) 3 B) 3
/ \ \
9 20 20
/ \ / \
15 7 15 7
The binary tree A is a height-balanced binary tree, but B is not.
Tags Expand
- Binary Search
- Divide and Conquer
- Recursion
思路
我的代码
/**
- Definition of TreeNode:
- public class TreeNode {
- public int val;
- public TreeNode left, right;
- public TreeNode(int val) {
- this.val = val;
- this.left = this.right = null;
- }
- } */
public class Solution { /**
* @param root: The root of binary tree.
* @return: True if this Binary tree is Balanced, or false.
*/
public boolean balanced = true;
public boolean isBalanced(TreeNode root) {
// write your code here
if (root == null) {
return true;
}
getHeight(root);
return balanced;
}
public int getHeight(TreeNode root) {
if (root == null) {
return 0;
}
int left = getHeight(root.left);
int right = getHeight(root.right);
if (Math.abs(left - right) > 1) {
balanced = false;
}
return Math.max(left, right) + 1;
}
} ```