save project

diy1.py

@@ -2,9 +2,13 @@
 #要求这个函数能接收一个名为num的整型参数
 #要求这个函数能计算1+2+3+……+num的结果
 def sum_numbers(num):
-    if num==1:
-        return(1)
-    a=sum_numbers(num-1)
+#    s=0
+#    for i in range(num,0):
+#        s=i+s
+#   return s
+    if num == 0:
+        return 0
+    a=sum_numbers(num+1)
     return a+num
-b=sum_numbers(100)
-print(b)
\ No newline at end of file
+b=sum_numbers(-5)
+print(b)