Linked List Get Intersection

LinkedListIntersection.java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode getIntersectionNode(ListNode headA, ListNode headB) {
        ListNode curr1 = headA;
        ListNode curr2 = headB;
        
        if (curr1 == null || curr2 == null) return null;
        
        int count1 = 0;
        int count2 = 0;
        while (curr1.next != null){
            curr1 = curr1.next;
            count1++;
        }
        while (curr2.next != null){
            curr2 = curr2.next;
            count2++;
        }
        
        if (curr1 != curr2){
            return null;
        }
        
        if (count1 == count2){
            if (count1 == 1) return headA;
            curr1 = headA;
            curr2 = headB;
            if (count1 == 1) return curr1;
            while (curr1 != curr2){
                curr1 = curr1.next;
                curr2 = curr2.next;
            }
            return curr1;
        }
        else if (count1 < count2){
            curr1 = headA;
            curr2 = headB;
            for (int i = 1; i <= count2 - count1; i++){
                curr2 = curr2.next;
            }
            while (curr1 != curr2){
                curr1 = curr1.next;
                curr2 = curr2.next;
            }
            return curr1;
            
        }
        else{
            curr1 = headA;
            curr2 = headB;
            for (int i = 1; i <= count1 - count2; i++){
                curr1 = curr1.next;
            }
            while (curr1 != curr2){
                curr1 = curr1.next;
                curr2 = curr2.next;
            }
            return curr1;
        }
        
        
    }
}