題目：輸入一棵二叉樹，判斷該二叉樹是否是平衡二叉樹。

class Solution {
public:
    bool IsBalanced_Solution(TreeNode* pRoot) {
        if (pRoot == NULL) return true;
        return IsBalanced_Solution(pRoot->left) && IsBalanced_Solution(pRoot->right)&&(abs(getHeight(pRoot->left)-getHeight(pRoot->right))<=1
 
);
    }
    int getHeight(TreeNode* root) {
        if (root == NULL) return 0;
        return max(getHeight(root->left), getHeight(root->right))+1;
    }
};