[LeetCode]Balanced Binary Tree

Balanced Binary Tree

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.

 

对每个节点计算该节点的深度，做过左右节点深度相差大于1，false。

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    int depthOfTree(TreeNode* root)
    {
        if(!root) return 0;
        return max(depthOfTree(root->left),depthOfTree(root->right))+1;
    }
    bool isBalanced(TreeNode* root) {
        if(!root) return true;
        if (abs(depthOfTree(root->left)-depthOfTree(root->right))>1) return false;
        bool left = isBalanced(root->left);
        bool right = isBalanced(root->right);
        return left&&right;
    }
};