题解 | #牛牛的绩点#
牛牛的绩点
https://www.nowcoder.com/practice/de8bc3e736164786b07a4dd64ed172f7
degree = {"A": 4, "B": 3, "C": 2, "D": 1,"F":0}
s=0
ave=0
while True:
a=dict()
c = input()
if c == "False":
break
d = int(input())
a[c] = d
for k, v in a.items():
s=s+v
av = degree[k] * v
ave=av+ave
print("%.2f" %(ave/s))
