北京术锐嵌入式软件笔试 9-17

《嵌入式软件开发笔试与面试手册》：https://blog.nowcoder.net/zhuanlan/jvN8gj

《软件开发笔试汇总》：https://www.nowcoder.com/creation/manager/columnDetail/0oDWVm

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1.32位CPU上,s1到s8的值分别是多少?如果值不确定请解释原因?

#include <stdint.h>
struct A{
	short s;
	uint32_t u1;
	union{
		char c;
		float f;
	};
	uint32_t u2;
	char cc;
};

struct B{
	char c;	
};


struct C{
	virtua1 ~C{}
	int i;
};


int main(){
	const char *a="1234";
	char b[]="1234";
	char c[4];
	auto s1 = sizeof(a);
	auto s2 = sizeof(b);
	auto s3 = sizeof(c);
	auto s4 = strlen(a);
	auto s5 = strlen(b);
	auto s6 sizeof(A);
	auto s7 = sizeof(B);
	auto s8 = sizeof(C);
	
	return 0
}

2

#include <iostream>
using namespace std;
class classA{
public:
	classA() { cout << " >> classA Ctor"; } 
	virtual ~classA() { cout << " >> classA Dtor"; } 

};

class interfaceB : public classA
{
public:
	virtual void method5() = 0;
};

class classB : public interfaceB{
public:
	classB() { cout << " >> ss classB Ctor"; }
	~classB() { cout << " >> ss classB Dtor"; }
	virtual void method5() {};
};

int main()
{
	classA a;
	classB *b = new classB();
	delete b;
	return 0;	
}

1.写出上面程序的执行结果

>> classA Ctor >> classA Ctor>> ss classB Ctor >> ss classB Dtor >> classA Dtor >>classA Dtor

2. main函数改成如下实现后，写出执行结果

int main()
{
	classA a;
	classA *b = new classB();
	delete b;
	return 0;	
}

>> classA Ctor >> classA Ctor>> ss classB Ctor >> ss classB Dtor >> classA Dtor >> classA Dtor

3

字符转换为大写int toupper(int c)

#include <iostream>
#include <cstring>
#include <cctype>
using namespace std;
class Mystring
{
private:
	char *representation;
public:
	Mystring( const char* );
	const char getupperstringO const;
};


MyString::Mystring( const char* new_string ){
	//增加实现代码
}

const char * MyString::getUpperString() const
{
	return representation;
}

int main()
{
	const Mystring Lowercase( "lower" );
	cout << Lowercase.getUpperString() << endl;
	return 0;
}

5.写ISOTCP/IP