Question

C++ codes ( please use Dev++ compiler )

please send the full program and please compile before send

linked list program with the delete function (and traverse)

void delNode(node** start, int delNum)

if there is no match, print an error message otherwise, delete node

do not forget the test plan and code

Answer 1

#include <iostream>
#include <cstdlib>
using namespace std;

// A linked list node
struct Node
{
int data;
struct Node *next;
};

void printList(struct Node *node)
{
while (node != NULL)
{
cout << " " << node->data << " ";
node = node->next;
}
}

/* Given a reference (pointer to pointer) to the head of a list and a key,
deletes the first occurrence of key in linked list */

void delNodeLinkedList(struct Node **start, int delNum)
{
// Store head node
struct Node* temp = *start, *prev;
  
// If head node itself holds the delNum to be deleted
if (temp != NULL && temp->data == delNum)
{
*start = temp->next; // Changed head
free(temp); // free old head
return;
}
  
// Search for the delNum(key) to be deleted, keep track of the
// previous node as we need to change 'prev->next'
while (temp != NULL && temp->data != delNum)
{
prev = temp;
temp = temp->next;
}
  
// If delNum(key) was not present in linked list
if (temp == NULL)
   {
       cout << "Element not found in the linked list.\n\n";
       return;
   }
  
// Unlink the node from linked list
prev->next = temp->next;
  
free(temp); // Free memory
}

int main()
{
struct Node* start = NULL;
struct Node* second = NULL;
struct Node* third = NULL;
struct Node* fourth = NULL;
struct Node* fifth = NULL;
  
// allocate 3 nodes in the heap   
start = (struct Node*)malloc(sizeof(struct Node));
second = (struct Node*)malloc(sizeof(struct Node));
third = (struct Node*)malloc(sizeof(struct Node));
fourth = (struct Node*)malloc(sizeof(struct Node));
fifth = (struct Node*)malloc(sizeof(struct Node));

start->data = 10; //assign data in first node
start->next = second; // Link first node with second

second->data = 20; //assign data to second node
second->next = third;   

third->data = 30; //assign data to third node
third->next = fourth;
  
fourth->data = 40;
fourth->next = fifth;
  
fifth->data = 50;
fifth->next = NULL;
  
cout << "List elements: \n";
printList(start);
  
cout << "\n\nDeleting node with value: 40\n";
delNodeLinkedList(&start, 11);
  
printList(start);
}

If there is anything that you do not understand, or need more help with then please mention it in the comments section.