LinkedList sorting a-z - c++

Question

Requirements for this function: If the full name (both the first and last name) is not equal to any full name currently in the list then add it and return true. Elements should be added according to their last name. Elements with the same last name should be added according to
their first names. Otherwise, make no change to the list and return false (indicating that the name is already in the list).
//this function add nodes to the list
//return true if fullname isn't in the list. Else return false if fullname is in the list.
//should be added according to last name.
bool OnlineDating::makeMatch(const std::string& firstName, const std::string& lastName, const OnlineType& value)
{
Node* p = head;
//are these nodes already set to firstName and lastName in this function
Node first;
Node last;
Node* temp = nullptr;
//if the list is empty just insert the fullname and value to the list
if (p == nullptr) {
//add values to the empty list
insertToRear(firstName, lastName, value);
return true;
}
else {
// so this loop is to check if fullname is in the list but first sort in alphebetial order
//sure its added in alphebetical order
//traverse the list after knowing where head is
while (p != nullptr) {
//checking to make sure theres at least another node in the list
if (p->next != nullptr) {
//its not going through ig loop?
//these are used to check and alphebetically selected names
if (p->last > p->next->last) {
insertToRear(p->first, p->last, p->value);
p->next = temp;
return true;
}
else if (p->next->last > p->last) {
insertToRear(p->first, p->last, p->value);
p->next = temp;
return true;
}
//check if full name is already in the list
if (p->last == p->next->last) {
insertToRear(p->first, p->last, p->value);
p->next = temp;
return true;
}
else if (p->first > p->next->first) {
insertToRear(p->first, p->last, p->value);
p->next = temp;
return true;
}
else {
//returns false if it passes through these checks
return false;
}
}
p = p->next;
}
}
}
Here is my main.cpp
int main()
{
OnlineDating clippersGonnaClip;
clippersGonnaClip.makeMatch("Kawhi", "Leonard", 2);
clippersGonnaClip.makeMatch("Paul", "George", 13);
clippersGonnaClip.makeMatch("Ivica", "Zubac", 40);
clippersGonnaClip.makeMatch("Reggie", "Jackson", 1);
clippersGonnaClip.makeMatch("Patrick", "Beverley", 21);
for (int n = 0; n < clippersGonnaClip.howManyMatches(); n++) {
string first;
string last;
int val;
clippersGonnaClip.confirmMatch(n, first, last, val);
cout << first << " " << last << " " << val << endl;
}
return 0;
}
honestly, I just want to create a ptr that will point to each node. Check as long as that node isn't pointing to nullptr, and sort the LinkedList in alphabetical order. finally link the nodes together using my *temp. Why won't it let me go through the if statements every time I compile I get a negative number? Every other function works for this program except this makeMatch(...).

Answer 1

Nothing in the requirements says anything about the data types you need to use. In this case using std::set makes most sense.
By providing a comparison operation on persons and a set you can guarantee uniqueness. Like this :
#include <set>
#include <string>
struct person_t
{
std::string name;
std::string last_name;
unsigned int age;
};
bool operator<(const person_t& lhs, const person_t& rhs)
{
if (lhs.last_name == rhs.last_name)
return lhs.name < rhs.name;
return lhs.last_name < rhs.last_name;
}
int main()
{
// set will ensure all persons are unique
std::set<person_t> persons;
persons.insert({ "Kawhi", "Leonard", 2 });
persons.insert({ "Paul", "George", 13 });
persons.insert({ "Ivica", "Zubac", 40 });
persons.insert({ "Reggie", "Jackson", 1 });
persons.insert({ "Patrick", "Beverley", 21 });
}