4. Intersection of Two Linked Lists

public class Solution {
    public ListNode getIntersectionNode(ListNode headA, ListNode headB) {
        
        //Length of List A
        int lenA=0;
        ListNode tempA = headA;
        while(tempA != null){
            lenA++;
            tempA = tempA.next;
        }
        
        //Length of B list
        int lenB=0;
        ListNode tempB = headB;
        while(tempB != null){
            lenB++;
            tempB = tempB.next;
        }
        
        int diff = Math.abs(lenA-lenB);
        
        //Iterate on larger list for diff nodes
        tempA=headA;
        tempB=headB;
        
        if(lenA > lenB) {
            while(diff-- > 0)
                tempA = tempA.next;
        }
        else {
            while(diff-- > 0)
                tempB = tempB.next;
        }
        
        //Check for equality
        while(tempA != tempB){
            tempA = tempA.next;
            tempB = tempB.next;
            if(tempA == null || tempB == null)
                return null;
        }
        return tempA;
    }
}

public class Solution {
    public ListNode getIntersectionNode(ListNode headA, ListNode headB) {
        ListNode tempA = headA;
        ListNode tempB = headB;
        while(tempA != tempB) {
            tempA = tempA != null ? tempA.next : headB;
            tempB = tempB != null ? tempB.next : headA;
        }
        return tempA;
    }
}