Linked list issue with multiple parameters - c++

Question

So I am trying to sort nodes according to their location (an integer) and then by the date (year and month). When I use my overloaded operator to print my linked list, it shows that the list is only inserting one of the wanted nodes meaning that my insert function is not correct. It is not giving any errors, it is just not running as expected. My insert function is below. Does anyone have any ideas as to what is wrong?
void LinkedList::insert(int location, int year, int month, double temperature) {
// Implement this function
Node* newNode = new Node();
newNode->loc = location;
newNode->yr = year;
newNode->mo = month;
newNode->temp = temperature;
Node* tempNode = head;
Node* previousNode = nullptr;
if(tail == nullptr & head == nullptr){
head = newNode;
}
while(tempNode != nullptr){
if((tempNode->loc == newNode->loc) && (tempNode->yr == newNode->yr)){
if(tempNode->mo > newNode->mo){
newNode->next = tempNode->next;
tempNode->next = newNode;
}
if(tempNode->mo < newNode->mo){
newNode->next = tempNode;
}
}
if(tempNode->loc > newNode->loc){
newNode->next = tempNode->next;
tempNode->next = newNode;
}
if(tempNode->loc < newNode->loc){
newNode->next = tempNode->next;
tempNode->next = newNode;
}
tempNode = tempNode->next;
}
}

Answer 1

The reason you are not getting the linkedlist properly is because you are making a mistake in pointer manipulation. When you assign cur->next=data->next;
you are basically breaking the list since data->next doesnot point to next node in the list.
Also, note that since this is a single linked list [meaning it has only one pointer forward] you can only insert nodes ahead of the current node.
Try something like this:
if (cur->loc > data->loc) {
data->next = cur->next; // This will insert data in middle of
cur->next = data; // cur and cur->next
}
There are multiple checks you will need to do if you want to insert in a increasing or decreasing order.
Make different cases for when you insert the first element of the list, insert at head, insert at tail and insert in the middle of linkedlist.
Also, at tail node make sure that its next is always set to null.