题解 | #二叉排序树#

#include <iostream>
#include <ratio>
using namespace std;

struct TreeNode
{
    int data;
    TreeNode* leftchild;
    TreeNode* rightchild;
    TreeNode(int x):data(x),leftchild(NULL),rightchild(NULL){}
};

TreeNode* Insert(TreeNode* root,int x,int father)
{
    if(root==NULL)
    {
        root=new TreeNode(x);//每次插入成功后，
        cout<<father<<endl;//求相应的父亲节点的关键字值

    }
    else if(x<root->data)
    {
        root->leftchild=Insert(root->leftchild,x,root->data);
    }
    else {
         root->rightchild=Insert(root->rightchild,x,root->data);
    }
    return root;
}


int main() {
    int n;
    while (cin >> n) { 
    TreeNode* root=NULL;//
        for(int i=1;i<=n;i++)
        {
            int x;
            cin>>x;
            root=Insert(root,x,-1);//不断更新root节点
        }
    }
}