LINKED LIST Append K

#1

my solution is not passing one test case
here is the code for append function :
public void appendLastN(int n) throws Exception {
int k=n%this.size;
if(k==0)return;
int index=(this.size-1-n)%this.size;
if(index<0)index=-index;
Node oldLast=this.getNodeAt(this.size-1);
Node toBeLast=this.getNodeAt(index);
Node NewHead=toBeLast.next;
toBeLast.next=null;
Node oldHead=this.head;
this.head=NewHead;
oldLast.next=oldHead;
}
can you please tell me where have i gone wrong

#2

Hi Kriti, save your code on ide.codingblocks.com and share the link here.

#3

here ma’am : https://ide.codingblocks.com/s/62858

#4

Hi Kirti, pls notice that it is given in question that k can be > n. Pls handle that case.
If you are given k > n then the result will be this

// Input
7 3
1 2 3 4 5 6 7

// Output
5 6 7 1 2 3 4

// Input
7 9
1 2 3 4 5 6 7

// Output
6 7 1 2 3 4 5

Pls try to see the thing in this case( k > n ). After that your code will work.

Hope this helps :slight_smile:

#5

i have made some changes but now its not giving output for one of the test case
here is my modified code :https://ide.codingblocks.com/s/65951
i have commented my append function for better understanding.plase point out my mistake in it

#6

Hi Kirti, none of these changes were required. The main problem was in tackling the case of k>n. This will be done by simply performing the following operation:

n = n%N // Variable Names acc to ur code.

for n = 4, N = 7 < in general k < n >
n = 4%7 = 4 itself
for n = 10, N = 7 < in general k < n >
n = 10%7 = 3

in line no. 251 of your code, you just have to pass n%N instead of just n;
I hope now you understand what do we mean if k>n.

Make this slight modification and it will work then. Hope this helps :slight_smile:

#7

thank you for your help :slightly_smiling_face:
i found my mistake my newhead was pointing towards null for some cases and yes as you have said the changes i made were not actually required :sweat_smile: