链表错误

Question

我只是在其中一个结构上测试函数，但是它不会到达它们。 这是到目前为止的完整代码：

更新

#include <iostream>
#include <string>
#include <cstdlib>
#include <cstddef>
using namespace std;

struct Node{
    string name;
    string address;
    int phoneNum;
    struct Node* next;
};

Node insertInOrder(Node p, string theName);
void push(struct Node*& head, string theName);


int main(){

    cout<<"\tEnter S or s to show the list contents \n"
        <<"\tEnter A or a to add a node to the list \n"
        <<"\tEnter D or d to delete a node from the list \n"
        <<"\tEnter Q or q to quiet the program \n"
    <<"Make your selection: "<<endl;

    struct Node* newNode = new Node;
    push(newNode, "yeah");

    cout<<newNode;

    return 0;

}

void push(struct Node*& head, string theName){
    struct Node* newNode = new Node;
    newNode->name = theName;
    newNode->next = head;
    head = newNode;
}

Node insertInOrder(Node p, string theName){
    if(p == NULL || p.name >= theName){
        return new Node(p, theName);
    }
    else{
            p.next = insertInOrder(p.next, theName);
            return p;
        }
    }

我收到一条错误消息：对于此代码，'sizeof'无法应用于不完整类型'Node'：

    void push(struct Node*& head, string theName){
    struct Node* newNode = malloc(sizeof(struct Node));
    newNode->name = theName;
    newNode->next = head;
    head = newNode;
}

我正在尝试将此代码转换为我的代码，但是我收到了一个错误：

 Node insertInOrder( int k, Node p ) {
   if( p == " " || p.item >= k ) 
      return new Node( k, p ); 
   else {
      p.next = insertInOrder( k, p.next ); 
      return p;
   }
} 

这就是我翻译它的方式：

Node insertInOrder(Node p, string theName){
    if(p == " " || p.name >= theName){
        return new Node(p, theName);
    }
    else{
            p.next = insertInOrder(p.next, theName);
            return p;
        }
    }

这是此代码的错误：

 if(p == " " || p.name >= theName){
        return new Node(p, theName);

错误：

- comparison with string literal results in unspecified behaviour [-Waddress]
- request for member ‘name’ in ‘p’, which is of pointer type ‘Node*’ (maybe you meant to use ‘-
 >’ ?)
- comparison between distinct pointer types ‘Node*’ and ‘const char*’ lacks a cast [-
 fpermissive]

p.next = insertInOrder（p.next，theName）; return p;

错误：

Invalid arguments ' Candidates are: Node insertInOrder(Node, std::basic_string<char,std::char_traits<char>,std::allocator<char>>) '
- could not convert ‘p.Node::next’ from ‘Node*’ to ‘Node’

Answer 1

有些观点：

• 忘记malloc，因为您正在使用C ++并使用new和delete
• 每次使用时都不需要再次指定该节点是结构，因此sizeof(Node)就足够了，但你不会直接使用malloc
• 你的函数Node insertInOrder(Node p, string theName)接受一个具体的节点并返回一个具体的Node，但你的结构中的下一个字段是指向Node的指针，我想你应该在你的内容中保持一致正在使用，因为你使用指针链接列表更合适
• 您不能在值和字符串文字（p == " "）之间直接使用比较运算符，您应该只检查name字段