DAY 1 作业

1、使用while循环输入 1 2 3 4 5 6     8 9 10

count = 0
while count < 10:
    count = count + 1  # count += 1
    if count == 7:
        continue
    print (count)

Pass 的方法：

count = 0
while count < 10:
    count = count + 1
    if count == 7:
        pass
    else：
　　 print (count)

2、求1-100的所有数的和

count = 1
sum = 0
while count <=100:
    sum = sum + count
    count = count + 1
print  (sum)

3、输出 1-100 内的所有奇数

count = 1
while count < 100:
    print(count)
    count = count + 2   √

方法2：
count = 1
while count < 101:
　　if count % 2 == 1:
　　　　print (count)
　　count += 1

4、输出 1-100 内的所有偶数

count = 2
while count < 100:
    print(count)
    count = count + 2

5、求1-2+3-4+5 ... 99的所有数的和

count = 1
count1 = 2
sum = 0
while count < 100:
    count = count + 2
    count1 = count1 + 2
　　 if count1 == 100;
　　　　　　 
    sum = sum + count - count1
print(sum) 　　　　　　　　　　　　　　错误，原因为只能求偶数次相加。

正确：

count = 1
sum = 0
while count < 100:
    if count % 2 == 1:
        sum += count
    else:
        sum -= count
    count += 1
print(sum)

6、用户登陆（三次机会重试）

account = "guo"
password = '12345'
a = 0
while a < 3:
    a = a + 1
    if input('请输入您的账户:') == account:
        a = 0
        while a < 3:
            a = a + 1
            if input('请输入您的密码：') == password:
                print('恭喜登陆')
                break

if a >= 3:
    print('您输入信息有误已超过3次,自动退出')

a = 0
while a < 3:
    account = input('请输入您的账户:')
    password = input('请输入您的密码：')
    if account == "guo" and password == '12345':
        print('恭喜登陆')
        break
    else:
        print('输入信息有误,请重新输入')
    a = a + 1