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.
Solution：包含两重递归，一是算degth，一是判断平衡
判断主节点的左右节点深度大小差，如果不在(-1,1)内，返回false，否则，继续判断其左右节点是否属于平衡二叉树
class Solution { public: int depth(TreeNode *node){ if(!node)return 0; return max(depth(node->left), depth(node->right))+1; } bool isBalanced(TreeNode* root) { if(!root)return true; int ldepth=depth(root->left); int rdepth=depth(root->right); return abs(ldepth-rdepth)<=1 && isBalanced(root->left) && isBalanced(root->right); } };
【LeetCode】110 - Balanced Binary Tree
原文：http://www.cnblogs.com/irun/p/4739450.html