趋势笔试_程序改错

绝地灬酷狼 2022-09-17 09:27 108阅读 0赞

收集了一些趋势的笔试题，主要是读代码改错的，大概是2011年和2012年的题目。大家就不需要在电脑上直接敲了

class base
    {
    public:
    	virtual ~base(){}
    	void work() {_do_work();}
    private:
    	virtual void _do_work();
    };
    
    class child:public base{
    	child();
    private:
    	void _do_work(){}
    
    };
    
    void main()
    {
    	child test;
    	test.work();
    
    	base *pb = &test;
    	pb->work();
    	child *pc = dynamic_cast<child*>pb;
    	pc->work();
    	delete pb;
    	return;
    }
    
    
    int a;
    int *b = &a;
    void myfunc(int *&c)
    {
    	a = 2;
    	cout<<*c<<endl;
    }
    
    void main()
    {
    	myfunc(b);
    }
    
    void main()
    {
    	char str[][4] = {
       {'1','2','3','4'},{'5','6','7','8'}};
    
    	char *pc1 = (char*)(&str+1);
    	char *pc2 = (char*)(&str[0] + 1 );
    	char *pc3 = (char *)(str + 1);
    	char c1 = *(pc2 - 1);
    	char c2 = *(pc2 - 1 );
    	char c3 = *(pc3-1);
    
    	cout<<c1<<endl;
    	cout<<c2<<endl;
    	cout<<c3<<endl;
    }
    
    
    #include <string>
    using namespace std;
    class Exception
    {
    public:
    	string &getExceptStr() {return _str;}
    public:
    	Exception():_str("Normal constructor string") {cout<<_str<<endl;}
    	Exception(const Exception &e ):_str("Copy constructor string")
    	{
    		cout<<_str<<endl;
    	}
    	Exception(string str):_str(str){ cout<<_str<<endl;}
    private:
    	string _str;
    };
    
    
    void main()
    {
    	try
    	{
    		Exception e(string("Init exception string"));
    		throw e;
    	}
    	catch (Exception &e)
    	{
    		string ecptstr = e.getExceptStr();
    	}
    	//return 0;
    }
    
    
    class base{
    public:
    	virtual void test() = 0;
    
    };
    
    class child:public base{
    public:
    	void test() {}
    private:
    	int _a;
    };
    
    class customer{
    public:
    	void visit(){if (_t) _t->test();}
    	customer(base *t):_t(t){}
    	~customer(){ delete _t;}
    private:
    	base *_t;
    };
    
    void main()
    {
    	customer c(new child());
    	c.visit();
    
    }
    
    
    2.2
    class Anamical{
    public:
    	int *p;
    	//Anamical(){}
    	Anamical(int value){
    		_name = new char[10];
    		if(!_name) throw "memory error";
    		memcpy(_name,0,10);
    	}
    	Anamical(Anamical &c){
    		_name = new char[10];
    		if(!_name) throw "memory error";
    		memcpy(_name,c._name,10);
    	}
    	~Anamical(){ if (_name) delete [] _name;}
    	void setName(string &name){
    		int len = name.length()>9?9:name.length();
    		memcpy(_name,name.c_str(),len);
    		_name[len] = 0;
    
    	}
    
    private:
    	char *_name;
    };
    
    void main()
    {
    	Anamical *dog,dog2;
    	dog = new Anamical;
    	dog->setName(string("dog"));
    	dog2 = *dog;
    	delete dog;
    }
    
    //2.3
    #define BUF_SIZE 255
    void make_dir(char dir[BUF_SIZE],const char *name)
    {
    	snprintf(dir,sizeof(*dir)*BUF_SIZE,"/usr/%s/bin",name);
    }
    
    int main(int argc,char *argv[]){
    	if(argc < 2)
    		return -1;
    	char dir[BUF_SIZE+1] = {0};
    	make_dir(dir,argv[1])
    }
    
    
    2.4
    class Klass{
    	Klass(){}
    	~Klass(){}
    	void func(int n){cout<<"Klass::func("<<n<<")";}
    public:
    	static Klass* GetInstance(){
    		static Klass *instance = 0;
    		if (instance == 0 )
    			instance = new Klass();
    		return instance;
    	}
    	static void Test(int n) { /*func(n);*/}
    
    };
    
    int main(){
    	Klass::GetInstance()->Test(10);
    	return 0;
    }
    
    class klass
    {
    public:
    	klass(){}
    private:
    	~klass(){}
    	void func(int n){
    		cout<<"klass!!"<<endl;
    	}
    public:
    	void test(){
    		func(100);
    	}
    };
    
    int main()
    {
    	klass *k = new klass;
    	k->test();
    	return 0;
    }
    
    //2.5
    class taskhandler{
    public:
    	virtual ~taskhandler() {}
    public:
    	virtual int handle(void *context) = 0;
    	virtual int finish(void *context) = 0;
    private:
    	int _handledTaskCount;
    };
    
    class ConvertTaskHandler:public taskhandler{
    	ConvertTaskHandler() {}
    	~ConvertTaskHandler() {}
    	int handle(void *context){
    		_handledTaskCount++;
    		return 0;
    	}
    	int finish(){return 0;}
    private:
    	int _charset;
    public:
    	static ConvertTaskHandler &getInstance(){ static ConvertTaskHandler task; return task;}
    
    };
    
    void main()
    {
    	ConvertTaskHandler &converhandler = ConvertTaskHandler::getInstance();
    	taskhandler *phandler = &converhandler;
    	ConvertTaskHandler *pconvertHandler = &converhandler;
    	const char filename[] = "c:\\convet.txt";
    	phandler ->handle((void*)filename);
    	pconvertHandler->finish();
    
    }
    
    2.6
    #include <errno.h>
    const string &getExecptionString(int &error){
    	switch(error){
    		case 1:
    			return string("Error 1");
    		case 2:
    			return (const string)
    	}
    }
    class A
    {
    public:
    	A(){cout<<"A ";}
    	A(A& a){cout<<"AA ";}
    	A operator=(A a) {cout<<"AAA ";return a;}
    };
    
    void main()
    {
    	A a;
    	A a1;
    	a1 = a;
    }
    
    class B1 { public: virtual void fb1(){}; };
    class B2 { public: virtual void fb2(){}; };
    class B3 { public: virtual void fb3(){}; };
    
    class A1 : virtual public B1, virtual public B2
    {
    public:
    	virtual void fa1(){};
    	virtual void fb1(){};
    	virtual void fb2(){};
    };
    
    class A2 : virtual public B1, virtual public B2, virtual public B3
    {
    public:
    	//virtual void fb1(){};
    	//virtual void fb2(){};
    };
    
    
    void main()
    {
    	cout<<sizeof(A1)<<endl;
    	cout<<sizeof(A2)<<endl;
    	cout<<sizeof(B1)<<endl;
    	cout<<sizeof(B2)<<endl;
    }