全面的MyString — 运算符重载

A:全面的MyString

总时间限制: 1000ms 内存限制: 65536kB

描述

程序填空，输出指定结果

#include <cstdlib>
#include <iostream>
using namespace std;
int strlen(const char * s) 
{	int i = 0;
	for(; s[i]; ++i);
	return i;
}
void strcpy(char * d,const char * s)
{
	int i = 0;
	for( i = 0; s[i]; ++i)
		d[i] = s[i];
	d[i] = 0;
		
}
int strcmp(const char * s1,const char * s2)
{
	for(int i = 0; s1[i] && s2[i] ; ++i) {
		if( s1[i] < s2[i] )
			return -1;
		else if( s1[i] > s2[i])
			return 1;
	}
	return 0;
}
void strcat(char * d,const char * s)
{
	int len = strlen(d);
	strcpy(d+len,s);
}
class MyString
{

// 在此处补充你的代码

};


int CompareString( const void * e1, const void * e2)
{
	MyString * s1 = (MyString * ) e1;
	MyString * s2 = (MyString * ) e2;
	if( * s1 < *s2 )
	return -1;
	else if( *s1 == *s2)
	return 0;
	else if( *s1 > *s2 )
	return 1;
}
int main()
{
	MyString s1("abcd-"),s2,s3("efgh-"),s4(s1);
	MyString SArray[4] = {"big","me","about","take"};
	cout << "1. " << s1 << s2 << s3<< s4<< endl;
	s4 = s3;
	s3 = s1 + s3;
	cout << "2. " << s1 << endl;
	cout << "3. " << s2 << endl;
	cout << "4. " << s3 << endl;
	cout << "5. " << s4 << endl;
	cout << "6. " << s1[2] << endl;
	s2 = s1;
	s1 = "ijkl-";
	s1[2] = 'A' ;
	cout << "7. " << s2 << endl;
	cout << "8. " << s1 << endl;
	s1 += "mnop";
	cout << "9. " << s1 << endl;
	s4 = "qrst-" + s2;
	cout << "10. " << s4 << endl;
	s1 = s2 + s4 + " uvw " + "xyz";
	cout << "11. " << s1 << endl;
	qsort(SArray,4,sizeof(MyString),CompareString);
	for( int i = 0;i < 4;i ++ )
	cout << SArray[i] << endl;
	//s1的从下标0开始长度为4的子串
	cout << s1(0,4) << endl;
	//s1的从下标5开始长度为10的子串
	cout << s1(5,10) << endl;
	return 0;
}

输入

无

输出

1. abcd-efgh-abcd-
2. abcd-
3.
4. abcd-efgh-
5. efgh-
6. c
7. abcd-
8. ijAl-
9. ijAl-mnop
10. qrst-abcd-
11. abcd-qrst-abcd- uvw xyz
about
big
me
take
abcd
qrst-abcd-

样例输入

无

样例输出

1. abcd-efgh-abcd-
2. abcd-
3. 
4. abcd-efgh-
5. efgh-
6. c
7. abcd-
8. ijAl-
9. ijAl-mnop
10. qrst-abcd-
11. abcd-qrst-abcd- uvw xyz
about
big
me
take
abcd
qrst-abcd-

来源Guo Wei

本机编译器大概不让重定义系统函数（给定代码并不能过编
信仰提交1A 妙妙

#include <cstdlib>
#include <iostream>
using namespace std;
int strlen(const char * s) 
{	int i = 0;
	for(; s[i]; ++i);
	return i;
}
void strcpy(char * d,const char * s)
{
	int i = 0;
	for( i = 0; s[i]; ++i)
		d[i] = s[i];
	d[i] = 0;
		
}
int strcmp(const char * s1,const char * s2)
{
	for(int i = 0; s1[i] && s2[i] ; ++i) {
		if( s1[i] < s2[i] )
			return -1;
		else if( s1[i] > s2[i])
			return 1;
	}
	return 0;
}
void strcat(char * d,const char * s)
{
	int len = strlen(d);
	strcpy(d+len,s);
}
class MyString
{
	char *p;
public:
	MyString(){
		p=new char[1];
        p[0]='\0';
	}
	MyString(const char *s){
		p=new char[strlen(s)+1];
		strcpy(p,s);
	}
	MyString(const MyString &s){
		p=new char[strlen(s.p)+1];
		strcpy(p,s.p);
	}
	~MyString(){if(p!=NULL) delete []p;}
	friend ostream & operator <<(ostream &o,const MyString &s){
		o<<s.p;
		return o;
	}
	char & operator [](int x){return p[x];}
	MyString & operator =(const MyString &s){
		if(p!=NULL) delete []p;
		p=new char[strlen(s.p)+1];
		strcpy(p,s.p);
		return *this;
	}
	MyString operator +(const MyString &s){
		char *tmp=new char[strlen(p)+strlen(s.p)+1];
		strcpy(tmp,p);
		strcat(tmp,s.p);
		return MyString(tmp);
	}
	MyString operator +(const char *s){
		char *tmp=new char[strlen(p)+strlen(s)+1];
		strcpy(tmp,p);
		strcat(tmp,s);
		return MyString(tmp);
	}
	MyString & operator +=(const char *s){
		char *tmp=new char[strlen(p)+strlen(s)+1];
		strcpy(tmp,p);
		strcat(tmp,s);
		if(p!=NULL) delete []p;
		p=tmp;
		return *this;
	}
	friend MyString operator +(const char *s,const MyString &z){
		return MyString(s)+z;
	}
	char * operator ()(int a,int len){
		char *tmp=new char[len+1];
		for(int i=0;i<len;i++) tmp[i]=p[a+i];
		tmp[len]='\0';
		return tmp;
	}
	friend bool operator <(const MyString &a,const MyString &b){
		return strcmp(a.p,b.p)==-1;
	}
	friend bool operator >(const MyString &a,const MyString &b){
		return strcmp(a.p,b.p)==1;
	}
	friend bool operator ==(const MyString &a,const MyString &b){
		return strcmp(a.p,b.p)==0;
	}
// 在此处补充你的代码
};


int CompareString( const void * e1, const void * e2)
{
	MyString * s1 = (MyString * ) e1;
	MyString * s2 = (MyString * ) e2;
	if( * s1 < *s2 )
	return -1;
	else if( *s1 == *s2)
	return 0;
	else if( *s1 > *s2 )
	return 1;
}
int main()
{
	MyString s1("abcd-"),s2,s3("efgh-"),s4(s1);
	MyString SArray[4] = {"big","me","about","take"};
	cout << "1. " << s1 << s2 << s3<< s4<< endl;
	s4 = s3;
	s3 = s1 + s3;
	cout << "2. " << s1 << endl;
	cout << "3. " << s2 << endl;
	cout << "4. " << s3 << endl;
	cout << "5. " << s4 << endl;
	cout << "6. " << s1[2] << endl;
	s2 = s1;
	s1 = "ijkl-";
	s1[2] = 'A' ;
	cout << "7. " << s2 << endl;
	cout << "8. " << s1 << endl;
	s1 += "mnop";
	cout << "9. " << s1 << endl;
	s4 = "qrst-" + s2;
	cout << "10. " << s4 << endl;
	s1 = s2 + s4 + " uvw " + "xyz";
	cout << "11. " << s1 << endl;
	qsort(SArray,4,sizeof(MyString),CompareString);
	for( int i = 0;i < 4;i ++ )
	cout << SArray[i] << endl;
	//s1的从下标0开始长度为4的子串
	cout << s1(0,4) << endl;
	//s1的从下标5开始长度为10的子串
	cout << s1(5,10) << endl;
	return 0;
}