题目描述:
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.
思路:当树的左子树的高度与右子树的高度相差小于一,且左右子树各自都为平衡二叉树时,树为平衡二叉树。
代码:
bool Solution::isBalanced(TreeNode *root) { if(root == NULL) return true; if(abs(treeHeight(root->left) - treeHeight(root->right)) > 1) return false; return isBalanced(root->left) && isBalanced(root->right); } int max(int a,int b) { return a > b ? a : b; } int Solution::treeHeight(TreeNode * root) { if(root == NULL) return 0; return max(treeHeight(root->left),treeHeight(root->right)) + 1; }
原文地址:http://blog.csdn.net/yao_wust/article/details/40627461