Question

Problem 1 Enhance the LinkedList class by adding following methods to do some more operations of the linked list: 1. insertAt(pos, data): inserts the element data at position pos of the list. If position exceeds the length of the list throw an exception. Example: List: 4 672 insertAt(2, 8) List: 4 6872 insertAt(0, 9) List: 946872 insertAt(-1,10) IllegalArgumentException List: 94 6872 insertAt(8, 12) IndexOutOfBoundsException List: 94 6872

Answer 1

Below the implementation of insertAt() method to the existing LinkedList class.

Copy the below method to your existing LinkedList class. Make minor modifications as per your class functionality and test.

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@Override

public void insertAt(int index, Object o) throws IllegalAccessException {

Node node = head;

Node prevNode = null;

//Throw IllegalArgumentException if index <0 or > size

if(index <0 || index > size){

throw new IllegalArgumentException("Insertion index out of range");

}else if (index == 0) { // if index = 0 means insertion at first node.

Node newNode = new Node();

newNode.data = o;

newNode.next = head;//current head node pointing to new node next.

head = newNode;// new node set as head node.

size++;

} else {

for (int i = 0; i < size; i++) {

if (i == index) {

Node newNode = new Node();

newNode.data = o;

newNode.next = prevNode.next;//link new node next to prevnode next

prevNode.next = newNode;//link new node to prev node next

size++;

break;

}

prevNode = node;

node = node.next;

}

}

}

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