diff --git a/diy.py b/diy.py
index e6e8e70..6072fb6 100644
--- a/diy.py
+++ b/diy.py
@@ -4,11 +4,12 @@ cost= {'苹果':5.2,'山竹':12.9,'香蕉':2.4,'荔枝':15,'葡萄':9.3,'桂圆'
 k=input('请输入水果名称：')
 v=input('请输入水果价钱：')
 # ?补充条件判断:
-    if # ?:
-        # ?更新价钱
-        print(k+'降价了，现价'+v+'元')
+if k in cost:
+    if cost[k]<float(v):
+        cost[k] = float(v)
+        print(k+'降价了,现价'+v+'元')
     else:
-        print(k+'涨价了，我们不买')
+        print(k+'涨价了,我们不买')
 else:
     cost[k] = float(v)
     print(k+'的价钱'+v+'元已上传~')