Create intersection-of-two-linked-lists.java

Author: GouravRusiya30

Java/intersection-of-two-linked-lists.java

@@ -0,0 +1,63 @@
+/**
+ * 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) {
+        
+        int lenA = getLinkedListLength(headA);
+        int lenB = getLinkedListLength(headB);
+        
+        ListNode head1 = headA;
+        ListNode head2 = headB;
+        
+        if(lenA > lenB){
+            int diff = lenA - lenB;
+            head1 = moveList(diff, head1);
+        }
+        else{
+            int diff = lenB - lenA;
+            head2 = moveList(diff, head2);
+        }
+        
+        while(head1 != null){
+            if(head1 == head2){
+                return head1;
+            }
+            else if(head1.next == head2.next){
+                return head1.next;
+            }
+            head1 = head1.next;
+            head2 = head2.next;
+        }
+        
+        return null;
+    }
+    
+    public int getLinkedListLength(ListNode head){
+        ListNode currentHead = head;
+        int len = 0;
+        
+        while(currentHead != null){
+            currentHead = currentHead.next;
+            len++;
+        }
+        
+        return len;
+    }
+    
+    public ListNode moveList(int difference, ListNode head){
+        while(difference != 0){
+                head = head.next;
+                difference--;
+            }
+        return head;
+    }
+}