lintcode_93_平衡二叉树

/**
 * Definition of TreeNode:
 * class TreeNode {
 * public:
 *     int val;
 *     TreeNode *left, *right;
 *     TreeNode(int val) {
 *         this->val = val;
 *         this->left = this->right = NULL;
 *     }
 * }
 */


class Solution {
public:
    /*
     * @param root: The root of binary tree.
     * @return: True if this Binary tree is Balanced, or false.
     */
    int judge(TreeNode *root) {
        // write your code here
        if(root==NULL)
            return 0;
        int l=judge(root->left);
        int r=judge(root->right);
        if(l==-1||r==-1||fabs(l-r)>1)
            return -1;
        return max(l,r)+1;
    }
    bool isBalanced(TreeNode * root) {
        // write your code here
        if(root==NULL)
            return 1;
        return judge(root)>0;
    }
};