Write a program that lets you know if you can have a key or not, based on your role at the school.
First ask for the user’s role at the school. They can be a student, administrator, or a teacher. (And remember that capitalization is important! ‘Student’ is not the same as ‘student’.)
Example 1: Administrator or Teacher
For example, if this was the input:
Are you an administrator, teacher, or student?: teacher
This should be the output:
Administrators and teachers get keys!
Example 2: Student
And if this was the input:
Are you an administrator, teacher, or student?: student
This should be the output:
Students do not get keys!
(Note: You should also be able to handle a situation where the user enters a value other than administrator, teacher or student and tell them they must be one of the three choices!)
Example 3: Other
If they input anything else:
Are you an administrator, teacher, or student?: secretary
This should be the output:
You can only be an administrator, teacher, or student!
Ответ:
1,5 Кбайта=1,5 * 1024 байта = 1,5 * 1024 *8 бит = 12288 бит
12288/3072 = 4 бита — на один символ
Значит N=2^4 = 16 символов в алфавите.
Один символ занимает:
frac{1, 5 cdot 1024 }{3072} = frac{1, 5}{3}=0,5 байт = 4 бит
(1,5 Кбайт = 1,5 cdot 1024 байт)
Мощность алфавита N (или количество символов в алфавите) равно 2^4=16
ответ: 16 символов содержит алфавит.
Х1*(Х2+Х3)*Х1+Х2+Х1*Х3
1) X1*X1=X1 (закон повторения). Имеем:
Х1*(Х2+Х3)+Х2+Х1*Х3
2) Раскрываем скобки:
Х1*Х2+Х1*Х3+Х2+Х1*Х3
3) X1*X3+X1*X3=X1*X3 (a+a=a — тот же закон повторения, только для сложения). Применяем и имеем:
Х1*Х2+Х1*Х3+Х2
4) Х1*Х2+Х2=X2 (правило склеивания). Имеем:
Х2+Х1*Х3
Решено. Все законы нетрудно проверить подставляя 0 или 1