构造、拷贝构造、赋值、析构

#include <iostream>
using namespace std;

class Node
{
public:
    Node(const char*str="",int a = 0):m_a(a)
    {
        if (str == NULL)
        {
            m_p = new char[1];
            m_p[0] = ‘\0‘;
        }
        else
        {
            m_p = new char[strlen(str)+1];
            strcpy(m_p, str);
            m_p[strlen(str)] = ‘\0‘;
        }
    }
    Node(const Node& n)
    {
        int len = strlen(n.m_p);
        m_p = new char[len + 1];
        strcpy(m_p,n.m_p);
        m_a = n.m_a;
    }
    Node& operator=(const Node& n)
    {
        if (this != &n)
        {
            Node temp(n);
            char* temp_str = temp.m_p;
            temp.m_p = m_p;
            m_p = temp_str;
            m_a = n.m_a;
        }
        return *this;
    }
    virtual ~Node()
    {
        delete m_p;
    }
private:
    char* m_p;
    int m_a;
};

int main()
{
    Node a("abcd",10);
    
    Node b(a);
    Node c;
    c = a;
}