Insert at Middle Specific Position in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new node with given data.

DSA C

struct Node* newNode(int data) {
    struct Node* node = (struct Node*)malloc(sizeof(struct Node));
    node->data = [1];
    node->next = NULL;
    return node;
}

Drag options to blanks, or click blank then click option'

Anode

BNULL

C0

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning NULL or 0 instead of the input data.

Using the variable name 'node' instead of 'data'.

The new node's data field should be set to the input parameter 'data'.

2fill in blank

medium

Complete the code to traverse the list until the position before insertion.

DSA C

struct Node* temp = head;
int i = 1;
while (i < [1] - 1 && temp != NULL) {
    temp = temp->next;
    i++;
}

Drag options to blanks, or click blank then click option'

Apos

Bdata

Chead

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'data' or 'head' instead of the position variable.

Incorrect loop condition causing infinite loop.

We traverse until the node before the desired position, so we use 'pos'.

3fill in blank

hard

Fix the error in linking the new node after the temp node.

DSA C

new_node->next = [1]->next;
[1]->next = new_node;

Drag options to blanks, or click blank then click option'

Atemp

Bhead

Cnew_node

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'head' or 'new_node' instead of 'temp' causes wrong linking.

Assigning NULL breaks the list.

We link the new node after 'temp', so 'temp' is used to access the next node.

4fill in blank

hard

Fill both blanks to check if position is valid and handle insertion at head.

DSA C

if (pos == 1) {
    new_node->next = [1];
    [2] = new_node;
} else {
    // insertion in middle or end
}

Drag options to blanks, or click blank then click option'

Ahead

Btemp

Cnew_node

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'temp' or 'new_node' instead of 'head' causes wrong head update.

Not updating head pointer leads to lost list.

When inserting at position 1, new_node points to current head, and head is updated to new_node.

5fill in blank

hard

Fill all three blanks to complete the insertAtPosition function.

DSA C

void insertAtPosition(struct Node** head_ref, int data, int pos) {
    struct Node* new_node = newNode(data);
    if (pos == 1) {
        new_node->next = [1];
        [2] = new_node;
        return;
    }
    struct Node* temp = *head_ref;
    int i = 1;
    while (i < pos - 1 && temp != NULL) {
        temp = temp->next;
        i++;
    }
    if (temp == NULL) {
        printf("Position out of range\n");
        free(new_node);
        return;
    }
    new_node->next = [3]->next;
    [3]->next = new_node;
}

Drag options to blanks, or click blank then click option'

A*head_ref

Ctemp

Dnew_node

Attempts:

3 left

💡 Hint

Common Mistakes

Not dereferencing head_ref correctly.

Using wrong pointer for linking new_node.

For position 1, new_node->next points to *head_ref and *head_ref is updated. For middle insertion, new_node->next and temp->next are linked.