I'm stuck on a C++ problem. I have to build a singly-linked-list from an array and then remove a node from the linked-list. To remove the node I MUST pass the node one prior to the node I want to delete to a function(ex: If the linked-list holds {1, 2, 3, 4, 5} and I want to delete the node containing 3, I MUST pass the node containing 2 to the function removeAfterSingle). My code will delete from anywhere in the middle without issue, but I can't free the memory of the deleted node and I can't delete the first or last nodes. This is my code:

#include using namespace std; struct singleNum { int num; singleNum *next; }; struct singleNum *head1 = NULL; void buildListSingle(int num); void removeAfterSingle(struct singleNum *ptr1); void printListSingle(); int main() { int data[] = { 1, 10, 15, 50, 2, 11, 100, 33, 22 }; int sizeData = sizeof(data) / sizeof(data[0]); int i; int key; struct singleNum *ptr; for (i = 0; i < sizeData; i++) { buildListSingle(data[i]); } cout << "The singly-linked-list is: "; printListSingle(); cout << "Enter an array element to be deleted: "; cin >> key; ptr = head1; while (ptr->next != NULL) { if (ptr->next->num == key) { removeAfterSingle(ptr); } else { ptr = ptr->next; } } cout << "New singly-linked-list: "; printListSingle(); system("pause"); return 0; } void buildListSingle(int num) { struct singleNum *listSingle = new(nothrow)singleNum; listSingle->num = num; listSingle->next = NULL; struct singleNum *temp; if (head1 == NULL) { head1 = listSingle; } else { temp = head1; while (temp->next != NULL) { temp = temp->next; } temp->next = listSingle; } } void removeAfterSingle(struct singleNum *ptr1) { struct singleNum *temp; temp = ptr1->next; ptr1->next = ptr1->next->next; delete[](temp); } void printListSingle() { struct singleNum *temp; if (head1 != NULL) { temp = head1; while (temp != NULL) { cout << temp->num << " "; temp = temp->next; } } cout << endl; }

If I uncomment delete[](temp); in the removeAfterSingle function then my IDE (Visual Studio) says there's a problem with the line if(ptr.next->num != NULL) in the while loop of main.

I've tried using if/else statements in the removeAfterSingle function to delete the last node but that just leads to nothing being deleted.

I'm haven't even begun to see how to remove the first node.

I'm not sure if I'm passing the node to function in the best way. I tried creating a pointer to a node and just passing the pointer like I would any other pointer but that never seemed to work correctly.

Please help!!!

Update: I think I'm good on the freeing the memory. Where I really need the help is when I need to delete the first and/or last nodes.