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133public class LinkedListImpl {
class Node {
int val;
Node next;
public Node(int val) {
this.val = val;
}
}
Node head = null, tail = null;
/*
* Adds node at the end of the current list
*/
public void addNode(int val) {
if (head == null) {
Node temp = new Node(val);
head = temp;
tail = temp;
} else {
tail.next = new Node(val);
tail = tail.next;
}
}
/*
* Adds node at the start of the current list
*/
public void addNodeAtStart(int val) {
if (head == null) {
Node temp = new Node(val);
head = temp;
tail = temp;
} else {
Node temp = new Node(val);
temp.next = head;
head = temp;
}
}
/*
* Adds node at the certain index.
*/
public void addNodeAtCertainIndex(int val, int index) {
Node temp = head;
int count = 0;
while (temp != null && ++count != index)
temp = temp.next;
Node node = new Node(val);
node.next = temp.next;
temp.next = node;
}
/*
* Removes the last node in the given list and updates tail node
*/
public void removeNode() {
Node temp = head;
while (temp.next != null && temp.next.next != null) {
temp = temp.next;
}
temp.next = null;
tail = temp;
}
/*
* Removes the first node in the given list and updates head node
*
*/
public void removeNodeAtStart() {
// The first node would become zombie and should be garbage collected after the
// below operation
head = head.next;
}
/*
* Removes the node at the given index in the given list and updates head node
*
*/
public void removeNodeAtCertainIndex(int index) {
Node temp = head;
int count = 0;
while (temp != null && ++count != index)
temp = temp.next;
temp.val = temp.next.val;
temp.next = temp.next.next;
}
/*
* Checks if a node with the given value exist in the list, returns true or
* false. Alternatively you can return the index too.
*/
public boolean search(int target) {
Node temp = head;
while (temp != null) {
if (temp.val == target) return true;
temp=temp.next;
}
return false;
}
/*
* Checks if a node with the given value exist in the list, returns the index of
* the given value in the list.
*/
public int searchAndReturnIndex(int target) {
Node temp = head;
int count = 0;
while (temp != null) {
count++;
if (temp.val == target) return count;
temp=temp.next;
}
return -1;
}
/*
* Prints the current list
*/
public void printLinkedList() {
System.out.println();
Node temp = head;
while (temp != null) {
System.out.print(" " + temp.val);
temp = temp.next;
}
}
}