Leetcode - Balanced Binary Tree

Question

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.

Java Code

public boolean isBalanced(TreeNode root) {
    if(root == null) return true;

    int depth1 = maxDepth(root.left);
    int depth2 = maxDepth(root.right);

    //如果当前节点的左右子树的深度差小于1，则继续判断左右子节点各自的左右子树的深度差是否小于1
    if( -2 < depth1 - depth2 && depth1 - depth2 < 2)
        return isBalanced(root.left) && isBalanced(root.right);
    else
        return false;
}

说明

• TreeNode类的定义和maxDepth函数见题目Maximum Depth of Binary Tree