I'm creating a skip list program for my Algorithms and Advanced Data Structure class. I was tasked with implementing a find & add method for the skiplist. Here is my program, I'm running into a segmentation fault when I add my second value into the skiplist. My first issue that I fixed was that I wasn't checking the first node in the list to see if it was nullptr, but that was not my only issue apparently. Add Method: void SkipList::add(const ElemType &el) { // Create a new node with the given element Node *newNode = new Node(el); // Get the height of the new node int newHeight = newNode->nodeHeight; // If the height of the new node is greater than the current list height, // update the list height. if (newHeight > listHeight) { listHeight = newHeight; } // Array to keep track of nodes to update Node *update[MAX_NUM_LISTS]; // Start from the top level Node *current = head[listHeight - 1]; // Initialize current correctly // If the list is empty, assign the first node to head if (head[0] == nullptr) { head[0] = newNode; } else { // Loop to traverse through list for (int i = listHeight - 1; i >= 0; i--) { // Move forward in the current level while (current->next[i] != nullptr && current->next[i]->elem < el) { current = current->next[i]; } // Store the node before which the new node should be inserted update[i] = current; } // Insert the new node at each level for (int i = 0; i < newHeight; i++) { newNode->next[i] = update[i]->next[i]; update[i]->next[i] = newNode; } } } Find Method: bool SkipList::find(const ElemType &el) const { // Start from the top level Node *current = head[listHeight - 1]; bool found = false; // Iterate through the levels of the skip list for (int i = listHeight - 1; i >= 0; i--) { // Move forward in the current level until reaching the end or finding a larger element while (current->next[i] != nullptr && current->next[i]->elem < el) { current = current->next[i]; } // Check if the current node's next node contains the target element if (current->next[i] != nullptr && current->next[i]->elem == el) { found = true; // Element found } } return found; // Element not found in the skip list } Main: int main() { ElemType inputs[] = {5, 7, 8, 10, 12, 17, 19, 22, 28, 31, 33, 35, 42, 51, 59}; SkipList list1; cout << "For list1 (same as in the slide 10 of Skip List1 Lecture Note):\n"; // for (int i=0; i(std::size(inputs)); i++) { cout << "add " << inputs[i] << endl; list1.add(inputs[i]); cout << "list1:\n" << list1 << endl; } if (list1.find(33)) cout << "33 is found!\n"; else cout << "33 is not found!!!!\n"; if (list1.find(70)) cout << "70 is found!\n"; else cout << "70 is not found!!!!\n"; if (list1.find(10)) cout << "10 is found!\n"; else cout << "10 is not found!!!!\n"; cout << "\n===================================\n"; cout << "For list2:\n"; ElemType inputs2[] = {19, 8, 17, 59, 12, 7, 5, 22, 28, 35, 33, 31, 42, 51, 10}; SkipList list2; for (int i = 0; i < static_cast(std::size(inputs2)); i++) { cout << "add " << inputs2[i] << endl.

1. I'm creating a skip list program for my Algorithms and Advanced Data Structure class. I was
tasked with implementing a find & add method for the skiplist. Here is my program, I'm running
into a segmentation fault when I add my second value into the skiplist. My first issue that I fixed
was that I wasn't checking the first node in the list to see if it was nullptr, but that was not my
only issue apparently.
Add Method:
void SkipList::add(const ElemType &el) {
// Create a new node with the given element
Node *newNode = new Node(el);
// Get the height of the new node
int newHeight = newNode->nodeHeight;
// If the height of the new node is greater than the current list height,
// update the list height.
if (newHeight > listHeight) {
listHeight = newHeight;
}
// Array to keep track of nodes to update
Node *update[MAX_NUM_LISTS];
// Start from the top level
Node *current = head[listHeight - 1]; // Initialize current correctly
// If the list is empty, assign the first node to head
if (head[0] == nullptr) {
head[0] = newNode;
} else {

2. // Loop to traverse through list
for (int i = listHeight - 1; i >= 0; i--) {
// Move forward in the current level
while (current->next[i] != nullptr && current->next[i]->elem < el) {
current = current->next[i];
}
// Store the node before which the new node should be inserted
update[i] = current;
}
// Insert the new node at each level
for (int i = 0; i < newHeight; i++) {
newNode->next[i] = update[i]->next[i];
update[i]->next[i] = newNode;
}
}
}
Find Method:
bool SkipList::find(const ElemType &el) const {
// Start from the top level
Node *current = head[listHeight - 1];
bool found = false;
// Iterate through the levels of the skip list
for (int i = listHeight - 1; i >= 0; i--) {
// Move forward in the current level until reaching the end or finding a larger element
while (current->next[i] != nullptr && current->next[i]->elem < el) {
current = current->next[i];
}

3. // Check if the current node's next node contains the target element
if (current->next[i] != nullptr && current->next[i]->elem == el) {
found = true; // Element found
}
}
return found; // Element not found in the skip list
}
Main:
int main()
{
ElemType inputs[] = {5, 7, 8, 10, 12, 17, 19, 22, 28, 31, 33, 35, 42, 51, 59};
SkipList list1;
cout << "For list1 (same as in the slide 10 of Skip List1 Lecture Note):n";
// for (int i=0; i(std::size(inputs)); i++)
{
cout << "add " << inputs[i] << endl;
list1.add(inputs[i]);
cout << "list1:n"
<< list1 << endl;
}

4. if (list1.find(33))
cout << "33 is found!n";
else
cout << "33 is not found!!!!n";
if (list1.find(70))
cout << "70 is found!n";
else
cout << "70 is not found!!!!n";
if (list1.find(10))
cout << "10 is found!n";
else
cout << "10 is not found!!!!n";
cout << "n===================================n";
cout << "For list2:n";
ElemType inputs2[] = {19, 8, 17, 59, 12, 7, 5, 22, 28, 35, 33, 31, 42, 51, 10};
SkipList list2;
for (int i = 0; i < static_cast(std::size(inputs2)); i++)
{
cout << "add " << inputs2[i] << endl;
list2.add(inputs2[i]);
cout << "list2:n"
<< list2 << endl;
}

5. if (list2.find(33))
cout << "33 is found!n";
else
cout << "33 is not found!!!!n";
if (list2.find(70))
cout << "70 is found!n";
else
cout << "70 is not found!!!!n";
if (list2.find(10))
cout << "10 is found!n";
else
cout << "10 is not found!!!!n";
return 0;
}