BST 삽입 + 임의의 노드 삭제 귀속 실현

#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
const int maxn = 2e5+32;
#define LL long long
const int inf = 0x3f3f3f3f;



class bst
{
public:
	struct node
	{
		int key;
		node *left;
		node *right;
		node(int k):key(k),left(nullptr),right(nullptr){}
	};

	node *head=nullptr;

	void insert(node *now,int key)
	{
		if(head==nullptr){
			node *temp=new node(key);
			head=temp;
			return;
		}
		if(key>now->key){
			if(now->right==nullptr){
				node *temp=new node(key);
				now->right=temp;
				return;
			}
			insert(now->right,key);
		}
		else if(key==now->key)
			return;
		else{
			if(now->left==nullptr){
				node *temp=new node(key);
				now->left=temp;
				return;
			}
			insert(now->left,key);
		}
	}
	void midout(node *now)// 
	{
		if(now!=nullptr){
			midout(now->left);
			printf("%d
",now->key);
			midout(now->right);
		}
	}
	node* findmin(node *now)
	{
		return now->left==nullptr?now:findmin(now->left);
	}
	node* deletemin(node *now)
	{
		if(now->left==nullptr){
			node *temp=now->right;
			delete now;
			return temp;
		}
		now->left=deletemin(now->left);
		return now;
	}
	node* deletekey(node *now,int key)
	{
		if(now->key==key){
			node* temp=findmin(now->right);// temp（ ）
			temp->right=deletemin(now->right);// ， ， temp right。
			temp->left=now->left;// left left
			return temp;
		}else if(now->keyright=deletekey(now->right,key);
			return now;
		}else{
			now->left=deletekey(now->left,key);
			return now;
		}
	}





};


int main()
{
	bst a;
	a.insert(a.head,10);
	a.insert(a.head,15);
	a.insert(a.head,7);
	a.insert(a.head,4);
	a.insert(a.head,8);
	a.midout(a.head);
	cout<