add solution 206[js]

Author: limbowandering

solution/206.Reverse Linked List/Solution.js

@@ -0,0 +1,14 @@
+const reverseList = function(head){
+  if(head == null){
+      return head;
+  }
+  let cur = head;
+  let pre = null, tmp = null;
+  while(cur != null){
+      tmp = cur.next;
+      cur.next = pre;
+      pre = cur;
+      cur = tmp;
+  }
+  return pre;
+}