题解 | 牛牛的绩点

# 映射字典
grad_map = {"A": 4.0, "B": 3.0, "C": 2.0, "D": 1.0, "F": 0.0}

# 初始化总成绩点与总学分
total_points = 0
total_credits = 0

# 循环读取输入，直到等级为’False‘ 结束
while True:
    grad = input().strip()
    # 判断等级是否为False
    if grad == "False":
        break
    # 获取等级对应的学分
    credit = float(input().strip())
    total_points += grad_map[grad] * credit
    total_credits += credit

# 判断总学分是否大于0
if total_credits > 0:
    # 计算GPA
    gpa = total_points / total_credits
    print(f"{gpa:.2f}")
else:
    print("0.00")