Segmentation Fault C++ - c++

Question

I am getting a "Segmentation fault (core dumped)" run-time error with the following code:
#include <iostream>
#include "Student.h"
#include "SortedList.h"
using namespace std;
#define BOUNDS 100
int main() {
SortedList *list = new SortedList(); // points to the sorted list object
Student *create[BOUNDS]; // array to hold 100 student objects
int num = 100000; // holds different ID numbers
// fills an array with 100 students of various ID numbers
for (int i = 0; i < BOUNDS; i++) {
create[i] = new Student(num);
num += 10;
}
// insert all students into the sorted list
for (int i = 0; i < BOUNDS; i++)
list->insert(create[i]);
// individually deletes each student
num = 100000;
for (int i = 0; i < BOUNDS; i++) {
delete list->find(num);
num += 10;
}
// insert all students into the sorted list
for (int i = 0; i < BOUNDS; i++)
list->insert(create[i]);
num = 100000;
for (int i = 0; i < BOUNDS; i++) {
list->remove(num);
num += 10;
}
cout << "test2" << endl;
delete list;
return 0;
}
I have narrowed the error down to the delete list; lines (or whichever one comes first). I am just wondering as to why this is and how to possibly fix it. Any insight on this matter would be useful.

Answer 1

You have two problems that I can see.
First, in this loop:
for (int i = 0; i < BOUNDS; i++) {
x = new Student(num);
num += 10;
}
You are creating a bunch of dynamic Students and putting the latest one in x and the previous one is lost. This creates 100 Students dynamically and 99 of them are leaked. Also it doesn't fill an array with Students like the comment above it says it does. I'm not sure what you're trying to do here so I can't comment on what you need to do instead.
Secondly, you are calling delete here:
delete list->find(num);
on Students that are in automatic storage (the stack) (because you filled the list with pointers to the Students in create which holds automatic Students), which leads to undefined behaviour and is probably the cause of your segfault. You don't need to deallocate these Students because they will be deallocated when the array goes out of scope at the end of main.

Answer 2

Without knowing how StudentList is implemented, this is kind of shot in the dark but...
list->insert(&create[i]); is adding a stack allocated object to the list, and then delete list->find(num); tries to delete this stack allocated object. You can't delete stack allocated objects.
In addition to this, your first for loop is leaking memory.
And I've been ninja'd.

Answer 3

This line has a problem:
list->insert(&create[i]);
At that point, create has been allocated, but nothing has been put into it. Probably the result of x = new Student(num) should be assigned there.

Answer 4

"create" array is allocated on stack. You are trying to delete stack allocated memory that's why you getting this error.
delete list->find(num);

Answer 5

You are definitely leaking memory:
// fills an array with 100 students of various ID numbers
for (int i = 0; i < BOUNDS; i++) {
x = new Student(num);
num += 10;
}
The x is leaked in this snippet, unless the ctor of Student somehow magically inserts itself somewhere, where the pointer can be tracked.
And that might or might be related to the crash.