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