# LinkedList insert, remove and change

• September 21st, 2011, 03:00 AM
Alexie91
Dear Experts,

I am new to the LinkedList concept and trying out coding a LinkedList problem which require me to do Insert newInteger based on the Index, Remove Index and Change oldInteger to newInteger based on Index.
Code :

``` public void insert(int index, int newInteger) { // implementation }   public void remove(int index) { // implementation } public void change(int index, int newInteger) { // implementation }```
------------------------------------------------------------------------------------
Sample input

4 8
1 5 2 3
4
I 1 2
R 2
C 1 10
I 4 2

Sample output

YES
NO
NO
NO
------------------------------------------------------------------------------------

Here is my full code:

Code :

```import java.util.*;   //use ListNode to represent the integers. class ListNode { protected Object element; protected ListNode next;   public ListNode(Object item){ element = item; next = null; } //declare constructors public ListNode(Object item, ListNode n){ element = item; next = n; } //get the next list node public ListNode getNext(){ return this.next; } public Object getElement(){ return this.element(); } }   class LinkedList { // declare the member field protected ListNode head = null; protected int num_nodes = 0;   public boolean isEmpty(){ return (num_nodes == 0); }   /* add: add a listNode to the linklist * PRE-Condition : * POST-Condition : */ public void add(ListNode listNode) { // implementation head = new ListNode (item, head); num_nodes ++; }   /* insert: insert a newInteger at index * PRE-Condition : * POST-Condition : */ public void insert(int index, int newInteger) { // implementation }   /* remove: remove the element at index * PRE-Condition : * POST-Condition : */ public void remove(int index) { // implementation }   /* change: change the integer at index with newInteger * PRE-Condition : * POST-Condition : */ public void change(int index, int newInteger) { // implementation }   /* isBetter: to compare between this linkedList with prevLinkedList * PRE-Condition : * POST-Condition : */ public String isBetter(LinkedList prevLinkedList) { // picking the integers in the newLinkedList and find out the difference between integers in the prevLinkedList // and sum the difference up. // if the sum of difference is more than K, return "YES" // else return "NO" int ans = 0; for (int i=0; i<prevLinkedList.size(); i ++){ prevLinkedList.element - element = ans; } return "YES"; } }   public class Main {   public static void main(String[] args) { // declare the necessary variables //int [] array; LinkedList <Integer>list = new LinkedList<Integer>(); int N; //indicate the size of array int K; //indicate the citeria int Q; //indicate the no.of entry String operator; //indicate if it is for insert, remove or change int index; //indicate the first input of operator int newInteger; //indicate the second input of operator int sum;   //declare a Scanner object to read input Scanner sc = new Scanner(System.in);   N = sc.nextInt(); K = sc.nextInt();   list = new int [N];   for (int i=0; i<list.size(); i++){ list.add(sc.nextInt()); }   Q = sc.nextInt();   for (int i=0; i<Q; i++){ operator = sc.next();   if(operator = "I"){ index = sc.nexInt(); newInteger = sc.nextInt(); //int post = index -1; } else if (operator = "R"){ index = sc.nextInt(); } else if (operator = "C"){ index = sc.nextInt(); newIntegter = sc.nexInt(); //int post = index -1; } } System.out.println(list.isBetter); } }```
• September 21st, 2011, 07:16 AM
KevinWorkman
Re: LinkedList insert, remove and change