python-12-1

# 课本63页例2
year = int(input("请输入一个年份"))
flag = False
if year % 4 == 0:
    if year % 100 == 0:
        if year % 400 == 0:
            flag = True
        else:
            flag = False
    else:
        flag = True
else:
    flag = False

if flag:
    print(str(year)+"是闰年")
else:
    print(str(year)+"不是闰年")



if year % 400 == 0 or year % 100 != 0 and year % 4 == 0  :
    print(str(year)+"是闰年")
else:
    print(str(year) + "不是闰年")


# 课本65页例3
username = input("请输入用户名")
pwd = input("请输入密码")
if username == "admin" and pwd == "123456":
    print("登录成功")
else:
    if username != "admin":
        print("用户名错误")
    if pwd != "123456":
        print("密码错误")



# 课本93页第四大题的第1小题

age = int(input("请输入一个年龄"))
if age >= 40:
    print("慢跑")
elif age <40 and age >= 30:
    print("竞走")
elif age < 30 and age >= 24:
    print("跳绳")
else:
    pass # 为了保证分支结构的完整性



# shenjiarui zhengxiaokun caixiaojun