Delete keys in a Linked list using C++ program

Delete keys in a Linked list using C++ program

In this program, we will see a C++ program through which we can delete keys in a linked list.

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

Example:

#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,4);
cout<<"\nAfter the delete operation"<<endl;
print(l);
return 0;
}