12 一个给定的数值由左边开始升位到右边第 N 位，如 0010$amp;<amp;$lt;1 == 0100 或者 0001 0011$amp;<amp;$l

12 一个给定的数值由左边开始升位到右边第 N 位，如

0010$amp;或者

0001 0011$amp;请用 C 或者 C++或者其他 X86 上能运行的程序实现。

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附加题（只有在完成以上题目后，才获准回答）

In C++, what does "explicit" mean？ what does "protected" mean？

explicit

C++ Specific

This keyword is a declaration specifier that can only be applied to

in-class constructor declarations. Constructors declared explicit will not

be considered for implicit conversions. For example:

class X {

public:

explicit X(int); //legal

explicit X(double) { //legal // ... }

};

explicit X::X(int) {} //illegal

An explicit constructor cannot take part in implicit conversions. It can

only be used to explicitly construct an object. For example, with the class

declared above:

void f(X) {}

void g(int I)

{

f(i); // will cause error

}

void h()

{

X x1(1); // legal

}

The function call f(i) fails because there is no available implicit

conversion from int to X.

Note It is meaningless to apply explicit to constructors with multiple

arguments, since such constructors cannot take part in implicit conversions.

END C++ Specific

protected

C++ Specific —>

protected: [member-list]

protected base-class

When preceding a list of class members, the protected keyword specifies

that those members are accessible only from member functions and friends of

the class and its derived classes. This applies to all members declared up

to the next access specifier or the end of the class.

When preceding the name of a base class, the protected keyword specifies

that the public and protected members of the base class are protected

members of the derived class.

Default access of members in a class is private. Default access of members

in a structure or union is public.

Default access of a base class is private for classes and public for

structures. Unions cannot have base classes.

For related information, see public, private, friend, and Table of Member

Access Privileges.

END C++ Specific

Example

// Example of the protected keyword

class BaseClass {

protected: int protectFunc();

};

class DerivedClass : public BaseClass

{ public:

int useProtect() { protectFunc(); } // protectFunc accessible from

derived class

};

void main()

{

BaseClass aBase;

DerivedClass aDerived;

aBase.protectFunc(); // Error: protectFunc not accessible

aDerived.protectFunc(); // Error: protectFunc not accessible in derived

class } How do you code an infinite loop in C？

请帮忙给出正确答案和分析，谢谢！