In my code 2 test case are pass and two test case are fail what is problem in my code

#1

public class list {
private class Node {
int data;
Node next;

	Node(int data, Node next) {
		this.data = data;
		this.next = next;
	}
}

private Node head;
private Node tail;
private int size;

public list() {
	this.head = null;
	this.tail = null;
	this.size = 0;
}

public list(Node head, Node tail, int size) {
	this.head = head;
	this.tail = tail;
	this.size = size;
}

// O(1)
public int size() {
	return this.size;
}

// O(1)
public boolean isEmpty() {
	return this.size() == 0;
}

// O(1)
public int getFirst() throws Exception {
	if (this.isEmpty()) {
		throw new Exception("List is empty.");
	}

	return this.head.data;
}

// O(1)
public int getLast() throws Exception {
	if (this.isEmpty()) {
		throw new Exception("List is empty.");
	}

	return this.tail.data;
}

// O(N)
public int getAt(int idx) throws Exception {
	Node temp = this.getNodeAt(idx);
	return temp.data;
}

// O(N)
private Node getNodeAt(int idx) throws Exception {
	if (this.isEmpty()) {
		throw new Exception("List is empty");
	}

	if (idx < 0 || idx >= this.size()) {
		throw new Exception("Invalid arguments");
	}

	Node retVal = this.head;
	for (int i = 0; i < idx; i++) {
		retVal = retVal.next;
	}

	return retVal;
}

// O(1)
public void addFirst(int data) {
	Node node = new Node(data, this.head);

	if (this.size() == 0) {
		this.head = node;
		this.tail = node;
	} else {
		this.head = node;
	}

	this.size++;
}

// O(1)
public void addLast(int data) {
	Node node = new Node(data, null);

	if (this.size() == 0) {
		this.head = node;
		this.tail = node;
	} else {
		this.tail.next = node;
		this.tail = node;
	}

	this.size++;
}

// O(n)
public void addAt(int idx, int data) throws Exception {
	if (idx < 0 || idx > this.size()) {
		throw new Exception("Invalid arguments");
	}

	if (idx == 0) {
		this.addFirst(data);
	} else if (idx == this.size()) {
		this.addLast(data);
	} else {
		Node nm1 = this.getNodeAt(idx - 1);
		Node n = nm1.next;

		Node node = new Node(data, n);
		nm1.next = node;

		this.size++;
	}
}

// O(1)
public int removeFirst() throws Exception {
	if (this.isEmpty()) {
		throw new Exception("List is empty");
	}

	int retVal = this.head.data;

	if (this.size() == 1) {
		this.head = null;
		this.tail = null;
	} else {
		this.head = this.head.next;
	}

	this.size--;
	return retVal;
}

// O(n)
public int removeLast() throws Exception {
	if (this.isEmpty()) {
		throw new Exception("List is empty");
	}

	int retVal = this.tail.data;

	if (this.size() == 1) {
		this.head = null;
		this.tail = null;
	} else {
		Node sm2 = this.getNodeAt(this.size() - 2);
		sm2.next = null;
		this.tail = sm2;
	}

	this.size--;
	return retVal;
}

// O(n)
public int removeAt(int idx) throws Exception {
	if (this.isEmpty()) {
		throw new Exception("List is empty");
	}

	if (idx < 0 || idx >= this.size()) {
		throw new Exception("Invalid arguments");
	}

	if (idx == 0) {
		return this.removeFirst();
	} else if (idx == this.size() - 1) {
		return this.removeLast();
	} else {
		Node nm1 = this.getNodeAt(idx - 1);
		Node n = nm1.next;
		Node np1 = n.next;

		nm1.next = np1;
		this.size--;

		return n.data;
	}
}

// O(n)
public void display() {
	Node node = this.head;

	while (node != null) {
		System.out.print(node.data + " ");
		node = node.next;
	}

	//System.out.println("END");
}
 
public static int intersectionPoint(Node headA,Node headB,int sizeA,int sizeB) {
	Node temp=headA;
	Node temp1= headB;
	
	int d=Math.abs(sizeA-sizeB);
	if(sizeA>sizeB){
		for(int i=0;i<d;i++){
			temp=temp.next;
		}
	}else{
		for(int i=0;i<d;i++){
			temp1=temp1.next;
	}
}
	while(temp.next!=null && temp1.next!=null) {
if(temp.data==temp1.data){
	return temp.data;
}
	temp=temp.next;
	temp1=temp1.next;
}
return -1;

}
public static void main(String[] args) throws Exception {
list list1 = new list();
Scanner scn=new Scanner(System.in);
int n1 = scn.nextInt();

			    for (int j = 0; j < n1; j++) {
				    int item = scn.nextInt();
				    list1.addLast(item);
			}

              list list2 = new list();
			    int n2 = scn.nextInt();
			 
			    for (int j = 0; j < n2; j++) {
				    int item = scn.nextInt();
				    list2.addLast(item);
			}
			System.out.println(intersectionPoint(list1.head,list2.head,list1.size(),list2.size()));

}
}

#2

@sksumitkumardiwaker,
I have edited your code: https://ide.codingblocks.com/s/197172
It was all correct except the while loop in intersection method. Kindly go through the changes.

#3

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