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how does this work? there is no link between the 2ndlast item (formerly the last) and the new one just added. Also current.next, when current is null woud return an NPE, wouldnt it?
I am not asking for a solution, I had already submitted a working one. So yes to answer your unnecessarily rude question, I do have an understanding of how linked lists work. But I do like to see others' solutions as well, and if better than mine, I like to improve. I noticed, he used current.next, which is the correct way to do it. I dont think questions are frowned upon here nor is there
Thank you for posting the solution. I'm new to linked lists but this clarified what I was supposed to be doing and now its much more clear. Understanding is better than aimless frustration.
According to the problem statement...
1.)You need to figure out a way if head=NULL i.e if the list is empty but when you declare "if(head->next==NULL)" it means that you are consider only the non empty case.
2.)Even in this above case you are just returning "newn" nut you need to return thr address of first node which is "head"!
try adding
if(head==NULL) block of statements also
thanks! nice one!
you can reduce complexity by removing while loop there, because anyway in recursion head moves as you pass newn2->next, so no need to check the condition whether it is pointing to the extreme
first, check if the head is null (means that its start with emapty list) then the first if condition will handle that
second, mantain head object by assigning its references to current then iterate over the current while current.next still containing Node, when it found current.next == null, means that current is the last Node, then it assign the new Node to Current.next and return the head
with this way, we makesure that current would never be found as null
you do not assign the address to pointer temp
Node* Insert(Node *head,int data)
{
Node *temp;
temp=new Node(); //That's the statement missing
temp->data = data;
temp->next = NULL;
if(head == NULL)
{
head = temp;
}
else
{
Node *p;
p = head;
while(p->next != NULL)
p = p->next;
p->next = temp;
}
return(head);
}
When you exit the while loop you have a pointer pointing to nowhere. It didn't matter on the Print exercise, but here it does.
In your else statement, create another Node* pointer variable (*tail, for instance), and make it receive your *p at each iteration.
At the last iteration, it will be pointing to the last Node structure, which will be the tail of the linked list. Then your p->next=temp; will work :-) !
solution.cc:46:1: error: ‘Node’ does not name a type; did you mean ‘modf’?
Node* Insert(Node head,int data)
^~~~
modf
solution.cc: In function ‘int main()’:
solution.cc:83:41: error: ‘insertNodeAtTail’ was not declared in this scope
SinglyLinkedListNode llist_head = insertNodeAtTail(llist->head, llist_item);
Here's my solution in C++14. The class definition of SinglyLinkedListNode specifies that the constructor has an argument which is the data part of the node to be inserted.
SinglyLinkedListNode* insertNodeAtTail(SinglyLinkedListNode* head, int num){
SinglyLinkedListNode* node = new SinglyLinkedListNode(num);
Works.
SinglyLinkedListNode *newNode = new SinglyLinkedListNode();
solution.cc:61:62: error: no matching function for call to ‘SinglyLinkedListNode::SinglyLinkedListNode()
So we do not have an empty constructor, but do have a constructor with parameters. The one who wrote the background of this task should be immediately exterminated.
You could definitely just return tmp, and in fact would be more efficient. I just did it this way for my own understanding of making it clear what my intention was. The intention being: if the list is empty, assign our new node (tmp) to the head.
Insert a Node at the Tail of a Linked List
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Node Insert(Node head,int data) { Node tmp = new Node(); tmp.data = data; tmp.next = null;
}
how does this work? there is no link between the 2ndlast item (formerly the last) and the new one just added. Also current.next, when current is null woud return an NPE, wouldnt it?
I am not asking for a solution, I had already submitted a working one. So yes to answer your unnecessarily rude question, I do have an understanding of how linked lists work. But I do like to see others' solutions as well, and if better than mine, I like to improve. I noticed, he used current.next, which is the correct way to do it. I dont think questions are frowned upon here nor is there
calm down.
Also when you submit a correct working solution, you can see everyone elses in on the leaderboard.
Never in the history of calming down has someone calmed down by being told to calm down.
lol
YOU WERE JUST ADDING FUEL TO THE FIRE. GROW UP!
perfect
Why did you post this?
Please dont post solution here. :/
why he is helping out us!!!!!!! you can't say that "stop posting solutions here"
apse ho gaya toh apna code post kar do
you shouldn't post a solution here. also you should probably add newNode->next = NULL. incase you wanna be able to add elements to it later
Thank you for posting the solution. I'm new to linked lists but this clarified what I was supposed to be doing and now its much more clear. Understanding is better than aimless frustration.
I tried doing mine recursively in C any idea what went wrong?
According to the problem statement... 1.)You need to figure out a way if head=NULL i.e if the list is empty but when you declare "if(head->next==NULL)" it means that you are consider only the non empty case. 2.)Even in this above case you are just returning "newn" nut you need to return thr address of first node which is "head"!
try adding if(head==NULL) block of statements also
ya bro u r right this is needed in this code....
You are making changes in head only, which is wrong. Take any other pointer & copy head into it & then proceed,rest your code seems absolutely fine.
you have not covered the condition where the head is null. if you want to do this in this manner , your code should be somthing like this:
Node* Insert(Node *head,int data) { if(head==NULL) { Node *newn=(Node *)malloc(sizeof(Node));
}
thanks! nice one! you can reduce complexity by removing while loop there, because anyway in recursion head moves as you pass
newn2->next, so no need to check the condition whether it is pointing to the extremeThanks ! your solution is good for me. I can undertant .
can someone explain me the else condition;)
Only problem with recursive one is how to return the start pointer of the list ...(i tried it tooo)
actually you are not using concept if head is already null then what will print.......
try in c++
typedef struct Node *list; list Insert(list head,int data) { if(head==NULL){ head = new Node; head->next=NULL; head->data=data; return head; } return Insert(head->next,data); }
In C++ the typedef is implicit so you don't need it
Wrong Answer! Some possible errors: 1. You returned a NULL value from the function. 2. There is a problem with your logic
No way to return the start pointer
bhai code post kar de yaar
something is wrong with you simple logic :)
how am i getting error???plz explainNode* Insert(Node *head,int data { Node n = (node)malloc(sizeof(node)); n->data=data; n->next=NULL; if(head==NULL) { return head=n; } else { Node *rhead = head; while(head->next!=NULL) { head=head->next; } head->next =n; return rhead; } }
It doesn't seem to accept recursive answers that are working in g++
first, check if the head is null (means that its start with emapty list) then the first if condition will handle that
second, mantain head object by assigning its references to current then iterate over the current while current.next still containing Node, when it found current.next == null, means that current is the last Node, then it assign the new Node to Current.next and return the head
with this way, we makesure that current would never be found as null
Please suggest , unable to find out mistake in this :
Showing no response in output :(
you do not assign the address to pointer temp Node* Insert(Node *head,int data) { Node *temp; temp=new Node(); //That's the statement missing temp->data = data; temp->next = NULL;
if(head == NULL) { head = temp; } else { Node *p; p = head; while(p->next != NULL) p = p->next; p->next = temp; } return(head); }
why is the above code giving me segmentation fault
When you exit the while loop you have a pointer pointing to nowhere. It didn't matter on the Print exercise, but here it does.
In your else statement, create another Node* pointer variable (*tail, for instance), and make it receive your *p at each iteration.
At the last iteration, it will be pointing to the last Node structure, which will be the tail of the linked list. Then your
p->next=temp;will work :-) !why is the above code giving me segmentation fault
pointer temp needs to have assigned an adress
nice code
This is my solution in C++14
thanks
what is the difference bet Node* temp and Node *temp.?
Apologies for the delay in reply.
There's no difference. Both the notations result in the same identifier declaration.
bro can u explain ur code?
solution.cc:46:1: error: ‘Node’ does not name a type; did you mean ‘modf’? Node* Insert(Node head,int data) ^~~~ modf solution.cc: In function ‘int main()’: solution.cc:83:41: error: ‘insertNodeAtTail’ was not declared in this scope SinglyLinkedListNode llist_head = insertNodeAtTail(llist->head, llist_item);
SinglyLinkedListNode* insertNodeAtTail(SinglyLinkedListNode* head, int data) {
}
can you please help me with this code?
Node* Insert(Node *head,int data) { struct Node *temp,*tail,*ptr; temp=new Node; temp->data=data; temp->next=NULL; if(head==NULL) { head=temp;} else { ptr=head; while(ptr!=NULL) { tail=ptr; ptr=ptr->next; } tail->next=temp; } return head;
}
bro i think you missed the struct function and above is the soln that worked for me pm me if you find any problem
Here's my solution in C++14. The class definition of SinglyLinkedListNode specifies that the constructor has an argument which is the data part of the node to be inserted.
SinglyLinkedListNode* insertNodeAtTail(SinglyLinkedListNode* head, int num){
}
Thank you
Works.
So we do not have an empty constructor, but do have a constructor with parameters. The one who wrote the background of this task should be immediately exterminated.
new_node = new SinglyLinkedListNode(data);
try this in 2nd line
how can i remove this error?
solution.cc:47:1: error: ‘Node’ does not name a type; did you mean ‘modf’?
please help.
Node *temp=new Node(); is not working in my code. can you explain it?
you need memory space before temp->data = data;
It's my suggestion below: Node *temp = (Node *)malloc(sizeof(Node)); temp->data = data; temp->NULL;
the statement p->next=temp; needs to be out of the while loop. You assign after you traverse the whole list, not at every node.
Node* Insert(Node *head,int data) { Node *temp=new Node(); temp->data=data; temp->next=NULL; if(head==NULL){ head=temp; } else{ Node *p; p=head; while(p->next !=NULL){ p=p->next; } p->next=temp; } return head; }
thanks
same as mine. did u resolve it.
in your while loop , it should not be there(p->next=temp).
you have to create new node and allocate memory to it by malloc or new in c++
In your code:
Why not simply return
tmpinstead of re-assigningheadtotmpand then returninghead?Just curious. Thanks!
You could definitely just return tmp, and in fact would be more efficient. I just did it this way for my own understanding of making it clear what my intention was. The intention being: if the list is empty, assign our new node (tmp) to the head.
thanku it helped a lot ...
Below approach is with recursion
@k_pradeep
What is the significance of this line: if(parent != null) parent.next = head;
this doesn't work
it's not working
var newNode = new SinglyLinkedListNode(data); if(head == null){ head = newNode; return head; }else{ var temp = head; while(temp.next!=null){ temp = temp.next; } temp.next = newNode; return head }
Hope this will helps you !! :)