Add solution for intersection of two linked lists

Author: paopao2

Intersection of Two Linked Lists.js

@@ -28,6 +28,33 @@ Your code should preferably run in O(n) time and use only O(1) memory.
  * }
  */
 
+// better solution
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+
+/**
+ * @param {ListNode} headA
+ * @param {ListNode} headB
+ * @return {ListNode}
+ */
+var getIntersectionNode = function(headA, headB) {
+    let nodeA = headA;
+    let nodeB = headB;
+    
+    while (nodeA !== nodeB) {
+        nodeA = (nodeA === null) ? headB : nodeA.next;
+        nodeB = (nodeB === null) ? headA : nodeB.next;
+    }
+    
+    return nodeA;
+};
+
 /**
  * @param {ListNode} headA
  * @param {ListNode} headB