Q:

Delete keys in a Linked list using C++ program

mahmoud2506
Save to bookmark
|
2022-05-08
|
  193 
0

Given a linked list and a key element, we have to delete the node from the linked list.

Explanation and example:

    If a linked list is like : 1 → 2 → 3 → 4 → 5 → 6

    Case I: (key is not head)
    The key value is 4
    After deleting that node the linked list is:1 → 2 → 3 → 5 → 6
    
    Case II: (key is head)
    The key value is 1
    After deleting that node the linked list is: 2 → 3 → 5 → 6

 

C++ programming, exam questions, C++ programming exam-questions,
login and add your own answer to this question

All Answers

mahmoud2506
2022-05-08
need an explanation for this answer? contact us directly to get an explanation for this answer

Algorithm:

To solve the problem there are two conditions,

  1. If the key node is the head of the linked list then we delete the node and point the head pointer to next node.
  2. If the key is not the head pointer of the linked list then simply delete that node.

C++ implementation:

#include <bits/stdc++.h>
using namespace std;

struct node{
    int data;
    node* next;
};

//Create a new node
struct node* create_node(int x){
    struct node* temp= new node;
    temp->data=x;
    temp->next=NULL;
    return temp;
}

//Enter the node into the linked list
void push(node** head,int x){
    struct node* store=create_node(x);
    if(*head==NULL){
        *head =store;
        return;
    }
    struct node* temp=*head;
    while(temp->next){
        temp=temp->next;
    }
    temp->next=store;
}

//Delete the middle node from the linked list
void delete_node(node** head,int x){
    if((*head)->next==NULL){
        *head=NULL;
        return;
    }
    struct node* temp=*head;
    if(temp->data==x){
    	temp=temp->next;
    	*head=temp;
    	return;
    }
    while(temp){
    	if(temp->data==x){
    		temp->data=temp->next->data;
    		temp->next=temp->next->next;
    		break;
    	}
    	temp=temp->next;
    }
}

//Print the list
void print(node* head){
	struct node* temp=head;
	while(temp){
		cout<<temp->data<<" ";
		temp=temp->next;
	}
}

int main()
{
    struct node* l=NULL;
    push(&l,1);
    push(&l,2);
    push(&l,3);
    push(&l,4);
    push(&l,5);
    push(&l,6);
    cout<<"Before the delete operation"<<endl;
    print(l);
    delete_node(&l,2);
    cout<<"\nAfter the delete operation"<<endl;
    print(l);
	
    return 0;
}

Output

 
Before the delete operation
1 2 3 4 5 6
After the delete operation
1 3 4 5 6

need an explanation for this answer? contact us directly to get an explanation for this answer

total answers (1)

Data Structure programs using C and C++ (Linked List Programs)
This question belongs to these collections

Similar questions

need a help?

find thousands of online teachers now
Reverse a Linked List in groups of given size usin... >>
<< Delete the middle node of a Linked List in C++...