binary search tree by smart pointers-CodePudding

I used row pointers to implement the binary search tree data structure and it worked perfectly, but when I replaced the row pointers with shared_ptr it compiles successfully but the program crashes due to unknown run-time error. Could you please help in this?

#include<iostream>
#include<memory>
class node{
public:
int data;
std::shared_ptr<node>left = std::make_shared<node>();
std::shared_ptr<node>right = std::make_shared<node>();
};

std::shared_ptr<node>CreateNode(int x);
void print_tree(const std::shared_ptr<node>&x);

int main(){
    auto root = std::make_shared<node>();
    root = CreateNode(12);
    root->left = CreateNode(9);
    root->right = CreateNode(14);
    root->left->right = CreateNode(10);
    root->left->right = CreateNode(11);
    print_tree(root);
    return 0;
}

std::shared_ptr<node>CreateNode(int x){
    std::shared_ptr<node>NewNode = std::make_shared<node>();
    NewNode->data = x;
    NewNode->left = NewNode->right = nullptr;
    return NewNode;
}

void print_tree(const std::shared_ptr<node>&x){ 
    if(x==nullptr) return;
    std::cout<<x->data<<std::endl;
    print_tree(x->left);
    print_tree(x->right);
}

CodePudding user response：

#include<iostream>
#include<memory>

class node
{
public:
    int data;
    std::shared_ptr<node>left;
    std::shared_ptr<node>right;
};

std::shared_ptr<node>CreateNode(int x);
void print_tree(const std::shared_ptr<node>&x);

int main()
{
    auto root = CreateNode(12);
    root->left = CreateNode(9);
    root->right = CreateNode(14);
    root->left->right = CreateNode(10);
    root->left->right = CreateNode(11);
    print_tree(root);
    return 0;
}

std::shared_ptr<node>CreateNode(int x)
{
    std::shared_ptr<node>NewNode = std::make_shared<node>();
    NewNode->data = x;
    NewNode->left = NewNode->right = nullptr;
    return NewNode;
}

void print_tree(const std::shared_ptr<node>&x)
{
    if(x==nullptr) return;
    std::cout<<x->data<<std::endl;
    print_tree(x->left);
    print_tree(x->right);
}

This works on my machine. I made left and right pointers in node class initially equal to nullptr, instead of creating new node because you can't know is it going to be used. And root to be initialized by result of CreateNode function.