linked list errors - algorithm

Question

I just test the function on one of the struct which is name but it won't reach them.
This is the full code so far:
update:
#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;
}
}
I get an error that says: invalid application of ‘sizeof’ to incomplete type ‘Node’ for this code:
void push(struct Node*& head, string theName){
struct Node* newNode = malloc(sizeof(struct Node));
newNode->name = theName;
newNode->next = head;
head = newNode;
}
I'm trying to translate this code into my code but I got an error:
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;
}
}
This is how I translated it:
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;
}
}
here is the error for this code:
if(p == " " || p.name >= theName){
return new Node(p, theName);
Errors:
- 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;
errors:
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

Some points:
forget malloc since you are working with C++ and use new and delete
you don't need to specify that node is a struct again whenever you use it so sizeof(Node) is enough, but you won't directly use malloc
your function Node insertInOrder(Node p, string theName) accepts a concrete Node and return a concrete Node but the field next inside your struct is a pointer to a Node, I guess you shoul be consistent in what you are using and since you are working with a linked list using pointers is more suitable
you can't use a comparison operator directly between a value and a string literal (p == " "), you should check name field only