add: reverseLinkedList solution

Author: Cyjin-jani

reverse-linked-list/Cyjin-jani.js

@@ -0,0 +1,19 @@
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+const reverseList = function (head) {
+  if (!head) return null;
+
+  let curr = head;
+  let prev = null;
+
+  while (curr !== null) {
+    const next = curr.next;
+    curr.next = prev;
+    prev = curr;
+    curr = next;
+  }
+
+  return prev;
+};