判断一棵二叉树是否为平衡二叉树

#include <iostream>
#include <vector>
#include <algorithm>
#include<stack>
#include<math.h>
#include<string>
#include<string.h>
#include<map>
using namespace std;

 // Definition for a binary tree node.
struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
 
class Solution {
public:
    //从叶子节点开始往上判断每一个节点的平衡因子
    bool isBalanced(TreeNode* root) {

        if (root == nullptr) {
            return true;
        }
        else {
            if (isBalanced(root->left) && isBalanced(root->right))
            {
                int left = 0;

                if (root->left == nullptr) {
                    left = -1;
                }
                else {
                    left = root->left->val;
                }

                int right = 0;
                if (root->right == nullptr) {
                    right = -1;
                }
                else {
                    right = root->right->val;
                }

                if (abs(left - right) < 2) {
                    root->val = left > right ? left + 1 : right + 1;//取较深的值
                    return true;
                }
                else {
                    return false;
                }

            }
            else {
                return false;
            }
        }
    }
};
TreeNode* insert(TreeNode* root, int x) {
    if (root == NULL) {
        TreeNode* temp = new TreeNode(0);
        temp->val = x;
        temp->left = NULL;
        temp->right = NULL;
        return temp;
    }
    if(x<root->val)
        root->left = insert(root->left, x);
    else
        root->right = insert(root->right, x);

    return root;
}
void Print(TreeNode* root) {
    if (root == NULL)
        return;
    Print(root->left);
    Print(root->right);
    cout << root->val << endl;
}
int main()
{
    TreeNode* root = NULL;
    int n, x;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> x;
        root = insert(root, x);
    }
    Solution A;
    cout << A.isBalanced(root) << endl;
    Print(root);
    return 0;
}