refactor: rename variables for solution

typescript/src/mergeTwoSortedLists/mergeTwoSortedLists.ts

@@ -9,33 +9,33 @@ export class ListNode {
 }
 
 export function mergeTwoLists(
-  l1: ListNode | null,
-  l2: ListNode | null
+  list1: ListNode | null,
+  list2: ListNode | null
 ): ListNode | null {
   // Create a new linked list that will contain the merged nodes
   const dummyHead = new ListNode(-1);
   let current = dummyHead;
 
   // We continue to merge nodes until there is at least one node in each list
-  while (l1 !== null && l2 !== null) {
-    if (l1.val <= l2.val) {
-      current.next = l1;
-      l1 = l1.next;
+  while (list1 !== null && list2 !== null) {
+    if (list1.val <= list2.val) {
+      current.next = list1;
+      list1 = list1.next;
     } else {
-      current.next = l2;
-      l2 = l2.next;
+      current.next = list2;
+      list2 = list2.next;
     }
     current = current.next;
   }
 
   // If there are nodes in the first list, add them to the end of the new list
-  if (l1 !== null) {
-    current.next = l1;
+  if (list1 !== null) {
+    current.next = list1;
   }
 
   // If there are nodes in the second list, add them to the end of the new list
-  if (l2 !== null) {
-    current.next = l2;
+  if (list2 !== null) {
+    current.next = list2;
   }
 
   return dummyHead.next;