Question

1. (10 pts) Define the nodes in the LinkedList. Create the LinkedList using the ListNode class. Create a method to find a node with given value in a LinkedList. Return the value is this value exists in the LinkedList. Return null if not exists. Use these two examples to test your method.

Example 1:

Input: 1 -> 2 -> 3, and target value = 3

Output: 3

Example 2:

Input: 1 -> 2 -> 3, and target value = 4

Output: null

Using Eclipse for Java

Answer 1

/*If you any query do comment in the comment section else like the solution*/

class ListNode
{
        Node head; 
        class Node
        {
                int val;
                Node link;
                Node(int d) { 
                        val = d; link = null; 
                }
        }                               
        public void push(int val)
        {       
                Node newNode = new Node(val);           
                newNode.link = head;
                head = newNode;
        }
        int searchByTarget(int target) {
                Node ptr = head;
                while(ptr != null) {
                        if(ptr.val == target) {
                                return target;
                        }
                        ptr = ptr.link;
                }
                return 0;
        }
        public static void main(String args[])
        {
                ListNode llist = new ListNode();
                llist.push(1);
                llist.push(2);
                llist.push(3);
                int target = 4;
                int res = llist.searchByTarget(target);
                if(res != 0)
                        System.out.println(res);
                else 
                        System.out.println("null");
        }
}