写一个简单的二叉树遇到了segmentation fault :11问题，求助

Question

本人小白，写了个简单的二叉树练习一下，代码如下，运行时会出现segmentation fault :11错误，求助各位大大帮忙看看是什么原因？

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

class Node {
private:
    int content;
    Node *left;
    Node *right;
public:
    Node(int a);
    ~Node();
    int getcontent();
    Node *getleft();
    Node *getright();
    void setleft(Node *a);
    void setright(Node *a);
};

Node::Node(int a):content(a), left(NULL), right(NULL){}

Node::~Node() {}

int Node::getcontent() {
    return content;
}

Node * Node::getleft() {
    return left;
}

Node * Node::getright() {
    return right;
}

void Node::setleft(Node *a) {
    this->left = a;
}

void Node::setright(Node *a) {
    this ->right = a;
}

void insert(Node *pre, Node a) {
    if (a.getcontent() < pre->getcontent()) {
        if(pre->getleft() == NULL) {
            pre->setleft(&a);
        } else {
            insert(pre->getleft(), a);
        }
    } else if (a.getcontent() >= pre->getcontent()){
        if (pre->getright() == NULL) {
            pre->setright(&a);
        } else {
            insert(pre->getright(), a);
        }
    }
    return;
}

void print(Node *a) {
    cout << a->getcontent() << " ";
    if (a->getleft()->getcontent()) {
        print(a->getleft());
    }
    if (a->getleft()->getcontent()) {
        print(a->getright());
    }
    return;
}

int main() {
    Node roof(5);
    for (int i = 0; i < 10; ++i) {
        int n;
        cin >> n;
        Node a(n);
        insert(&roof, a);
    }
    print(&roof);
    return 0;
}

Answer 1

一般是指针一类的问题，自己调试下