﻿ C++ - Delete the last node of a Singly Linked List

# C++ Linked List Exercises: Delete the last node of a Singly Linked List

## C++ Linked List: Exercise-12 with Solution

Write a C++ program to delete the last node of a Singly Linked List.

Test Data:
Original list:
7 5 3 1
Remove the last node of the said list:
Updated list:
7 5 3
Again remove the last node of the said list:
Updated list:
7 5

Sample Solution:

C++ Code:

`````` #include <iostream> // Including input-output stream header file

using namespace std; // Using standard namespace

struct Node // Declare a structure for defining a Node
{
int num; // Data field to store a number
Node *next; // Pointer to the next node
}; // Node constructed

int sizen = 0; // Initializing variable to keep track of the size of the linked list

// Function to insert a node at the start of the linked list
Node* new_Node = new Node(); // Creating a new node
new_Node->num = num; // Assigning data to the new node
new_Node->next = *head; // Pointing the new node to the current head
sizen++; // Increasing the size of the linked list
}

// Function to delete the last node of the linked list
if (head == NULL) // Base case: if the list is empty
return NULL;

if (head->next == NULL) { // Base case: if there's only one node in the list
return NULL;
}

Node* second_last_node = head; // Locate the second last node
while (second_last_node->next->next != NULL)
second_last_node = second_last_node->next;

delete (second_last_node->next); // Remove the last node from the list
second_last_node->next = NULL; // Change the next of the second last node to NULL

}

// Function to display all nodes in the linked list
void display_all_nodes(Node* node) {
while (node != NULL) { // Loop through all nodes until the end is reached
cout << node->num << " "; // Displaying the data in the current node
node = node->next; // Move to the next node
}
}

int main() {

insert(&head,1); // Inserting a node with value 1
insert(&head,3); // Inserting a node with value 3
insert(&head,5); // Inserting a node with value 5
insert(&head,7); // Inserting a node with value 7

cout << "Original list:\n"; // Displaying message for the original list
display_all_nodes(head); // Displaying all nodes in the original list

cout << "\n\nRemove the last node of the said list:"; // Displaying message for removal of last node
cout << "\nUpdated list:\n";
display_all_nodes(head); // Displaying all nodes after removal

cout << "\n\nAgain remove the last node of the said list:"; // Displaying message for removal of last node again
cout << "\nUpdated list:\n";
head = delete_last_node(head); // Removing the last node of the list again
display_all_nodes(head); // Displaying all nodes after removal

cout << endl; // Displaying newline
return 0; // Returning from the main function
}
``````

Sample Output:

```Original list:
7 5 3 1

Remove the last node of the said list:
Updated list:
7 5 3

Again remove the last node of the said list:
Updated list:
7 5
```

Flowchart:

CPP Code Editor:

Previous C++ Exercise: Delete a middle node from a Singly Linked List.
Next C++ Exercise: Delete the nth node of a Singly Linked List from end.

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