Sorting using Linear Linked List in C++ - c++

Question

So I'm trying to build a linear linked list that takes info from users and saves the info in two sorted lists by name (alphabetically) and by birthdate. So far I have
struct node{
char* name;
int birthDate;
node *nameNext;
node * dateNext;
};
where each node will have two pointers pointing to the appropriate list. The problem I'm having is how to direct the head pointer node *head. How do I set head when there are two different lists? I'm thinking something like head->nameNext and head->dateNext but that would point to the second node of the lists if it work. Please help! Thanks in advance.

Answer 1

if i got your question right, you're simply looking to sort your list
in two ways (alphabetically and birthdate)
note: i will use bubble sort to simplify the algorithm but you can use better one as you know
#include <iostream>
struct node{
const char* name;
int birthdate;
node*next;
};
struct sort_data{
private:
node *name_root = nullptr; // alphabetically head/root pointer
node *date_root = nullptr; // birthdate head/root pointer
public:
void push(const char*name,int birthdate); // push data;
void sort_by_birth(); // sort the birth linked list
void sort_by_alphabet(); // sort the alphabet linked list
void print_birth(); // print the data of the birth linked list
void print_alph(); // print of the data of the alphabet linked list
};
void sort_data::push(const char*name,int birthdata) {
node*Name = new node; // allocate a node for the alphabet list
node*Date = new node; // allocate a node for the date list
Name->name = Date->name = name;
Name->birthdate = Date->birthdate = birthdata;
Name->next = name_root;
Date->next = date_root;
name_root = Name;
date_root = Date;
}
void sort_data::sort_by_birth() {
node*i = date_root;
node*j;
if(!i) // if i == nullptr
return;
while(i){ // while(i!=nullptr)
j = i->next;
while(j){
if(i->birthdate > j->birthdate){
std::swap(i->birthdate,j->birthdate);
std::swap(i->name,j->name);
}
j = j->next;
}
i = i->next;
}
}
void sort_data::sort_by_alphabet() {
node*i = name_root;
node*j;
if(!i)
return;
while(i){
j = i->next;
while(j){
if(i->name[0] > j->name[0]){
std::swap(i->birthdate,j->birthdate);
std::swap(i->name,j->name);
}
j = j->next;
}
i = i->next;
}
}
void sort_data:: print_birth(){
node*temp = date_root;
while(temp){
std::cout << temp->name << " " << temp->birthdate << std::endl;
temp = temp->next;
}
}
void sort_data::print_alph() {
node*temp = name_root;
while(temp){
std::cout << temp->name << " " << temp->birthdate << std::endl;
temp = temp->next;
}
}
int main(){
sort_data obj;
obj.push("jack",1997);
obj.push("daniel",1981);
obj.push("maria",1995);
obj.push("john",2008);
obj.sort_by_alphabet();
obj.sort_by_birth();
std::cout << "alphabetically : \n" ;
obj.print_alph();
std::cout << "by birthdate : \n";
obj.print_birth();
}
note: because you're using C++ don't use char* to store string literals
use std::string or const char *. as the chars in string literals are const char so you don't want to point on const char with char
if you're using a C++ compiler that support C++11 your compiler should generate a warning about such thing