题解 | #判断是不是平衡二叉树#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 *	TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param pRoot TreeNode类 
     * @return bool布尔型
     */
    int deep(TreeNode* root)
    {
        if(root == nullptr)
        {
            return 0;
        } 

        int left = deep(root->left);
        int right = deep(root->right);
        return (left > right) ? left + 1 : right + 1;
    }
    bool IsBalanced_Solution(TreeNode* pRoot) 
    {
        if(pRoot == nullptr)
        {
            return true;
        }

        int left = deep(pRoot->left);
        int right = deep(pRoot->right);

        if(left - right > 1 || left - right < -1)
        {
            return false;
        }

        return IsBalanced_Solution(pRoot->left) && IsBalanced_Solution(pRoot->right);
    }
};