wbbj.cpp

一个简单的文本编辑器．能实现基本的文本编辑

//
//*****************文本编辑器******************//
//**********    作者： happy_zh      **********//
//
//*****************This is a word editor.*****************//
//You can input at most 100 chars.Every time after you input the letters,//
//be sure to input a '#' to show stop and over.                          //
//程序中s1是操作的对象，程序还用了一个s2，对s1操作的时候，把操作的结果暂时
//送入s2，操作完成，再把s2赋给s1。这样虽然有时候浪费了空间，但思想简单。

const int MaxSize = 100;
#include<iostream.h>

class	Str{
	public:
        Str();
		void input_str();
		void copy_str(Str &s1,Str s2);
		void print_str(Str &s);
        void go_on_input(Str &s);
	    void delete_str(Str &s1,Str s);
        void insert_str(Str &s,Str s2,Str ss);
        void find_position(Str &s,Str &ss,int &n);
        void instead_str(Str &s1,Str s2,Str ss1,Str ss2,int n);
	
		char ch[MaxSize]; 
		int len;
        int position[100];  
		int y;
		int n;
		int b;
		int p;
};

//
Str::Str(){ char *ch; ch=new char [MaxSize];  }

//下面的程序为：输入一个字符串，输入#表示结束。
void Str::input_str()
{   
	cout<<"now input a new str,please. # means over.\n";

    int k;
	k=0; 
	ch[k]='x'; 
    while( cin>>ch[k],ch[k]!='#' )  k++;

	ch[k]='#';
	len=k;
}

//下面的程序为：显示整个字符串。

void Str::print_str(Str &s1)
{
	cout<<"\n●The string is:";
	for(int k=0;s1.ch[k]!='#';k++)
		cout<<ch[k];
	cout<<"\n\n";
}

//下面的程序为：拷贝现在的字符串，并连接在现在的字符串后面。
//复制s1，把连接的字符串赋给s2,再赋给s1。
void Str::copy_str(Str &s1,Str s2)
{   
    int p=0;
	for( int k=0; k<s1.len ; k++)
	{
		s2.ch[p]=s1.ch[k];  
	    p++;
	}                    
	for( k=0;  k<s1.len;  k++)
	{
		s2.ch[p]=s1.ch[k];  
	    p++;
	}                    
    s2.len=p; 
	cout<<"the length of the string is : "<<s2.len<<'\n';
	s2.ch[p]='#';

    for(int q=0; s2.ch[q]!='#'; q++)
		s1.ch[q]=s2.ch[q];
		s1.ch[q]='#';
		s1.len=s2.len;
    s1.print_str(s1);
}

//在现在的字符串后面继续输入字符，输入#表示结束。
void Str::go_on_input(Str &s)
{   
	cout<<"  # means over.\n";
	for(int w=0;s.ch[w]!='#';w++)
		cout<<ch[w];
	int k;
	k=s.len; 
	s.ch[k]='x'; 
    while( cin>>ch[k],ch[k]!='#' )  {cout<<ch[k];k++;}

	ch[k]='#';
	len=k;
	cout<<"the length of the string is : "<<len<<'\n';
	s.print_str(s);
}

//下面的程序为：删除字符串的一部分。
//原来字符串为s1，输入想从字符串上开始删除的位置，再输入删除的字符串长度，
//程序把字符串处理后，传给s2，s2再传回s1。

void Str::delete_str(Str &s1,Str s)
{ 
	cout<<"Input the position you want to start the deletion,please.\n";
	int i;
	cin>>i; 
	if(i>s1.len) cout<<"too big.\n";
	else { cout<<"Input the length you want to delete,please.\n";
	       int j;
		   cin>>j;  
		   if(i+j>s1.len)  cout<<"too many.\n";
		   else { 
			      int p=0;
		          for (int k=0;k<i;k++)
				  {s.ch[p]=s1.ch[k];p++;}

				  for (k=i+j;k<s1.len;k++)
				  {s.ch[p]=s1.ch[k];p++;}

				  s.len=p+1;
				  s.ch[p+1]='#';
				  
				  for(int q=0; s.ch[q]!='#'; q++)
					  s1.ch[q]=s.ch[q];
				  s1.ch[q-1]='#';
				  s1.len=s.len-1;
                  cout<<"Delete succeed.\n";
				  s1.print_str(s1);
		   }
	}
}

//下面的程序为：在字符串内插入一段字符串。
//先输入插入位置，再输入要插的字符串。

void Str::insert_str(Str &s,Str s2,Str ss)
{   
    cout<<"Input the position you want to insert , please. \n";
	int i;
	cin>>i;
	i--;
	if(i>s.len) cout<<"too large.\n";
	else {
		cout<<"input a string you want to insert ,please.'#' means over.\n";
	    int r; r=0; ss.ch[r]='x';
		while( cin>>ss.ch[r],ss.ch[r]!='#' )   r++; 
            	ss.ch[r]='#';
	            ss.len=r;

		  if(ss.len>MaxSize|| ( s.len +ss.len )>MaxSize)
			  cout<<"too long.\n";
          else {
			  int p=0;
			  for (int k=0; k<=i; k++)
			  {   
				    s2.ch[p]=s.ch[k];
					
					p++;
			  }
			  
			  for(k=0;k<ss.len;k++)
			  {   
				  s2.ch[p]=ss.ch[k];  
				  p++;
			  }
			  
              for(k=i+1;k<s.len;k++)
			  {
				  s2.ch[p]=s.ch[k];
				  p++;
			  }

			  s2.len=p;  cout<<"the length is "<<s2.len;
			  s2.ch[p]='#';  
			  
              for(int q=0; s2.ch[q]!='#'; q++)
					  s.ch[q]=s2.ch[q];
				  s.ch[q]='#';
				  s.len=s2.len ;
				  
              cout <<"insert succeed.\n";
			  print_str(s);
		  }
		  }
}

//下面的程序为：在字符串内寻找你想要的一段字符串，显示找到的位置。

void Str::find_position(Str &s,Str &ss,int &n)
{
	cout<<"input a small string you want to find ,please.\n";
    ss.input_str();  
	int y=0;  
	for(int i=0;i<s.len;i++)
	{  
		for(int j=i,k=0; s.ch[j]==ss.ch[k]; j++,k++)
		{   
			if(k==ss.len-1)
			{   cout<<"the position is  "<<i+1<< " .\n";
		    	position[y]=i+1; 
				y++;
			}
		}
	}
	if(!y)  {cout<<"none\n"; position[y]=-1;}
	
	 n=y;  //n表示字符串内有n个你想要的小段字符串。
}

//下面的程序为：在字符串内，把某些小段字符串替换为你想要的字符串。
//先输入你要改变的小段字符串，程序先找到这些字符串，再输入想要替换成的
//字符串，程序完成替换功能。
void Str::instead_str(Str &s1,Str s2,Str ss1,Str ss2,int n)
{
	s1.find_position(s1,ss1,n);
    
	if(n!=0) 
	{
	     cout<<"input a string you want to take the place of the old one.\n";
	
	     ss2.input_str();
	     cout<<"ok";
	
         cout<<"s1.len="<<s1.len;
	     cout<<"  ss1.len="<<ss1.len;
	     cout<<"   ss2.len="<<ss2.len;
	     cout<<"   n="<<n;
         cout<<(s1.len-(ss1.len-ss2.len)*n);

	     if(  (s1.len-(ss1.len-ss2.len)*n)>MaxSize)
	          cout<<"too long.\n";
         else 
		 {   
			 int p=0;
			 position[n]=s1.len+1;

			 for(int i=0;i<position[0]-1;i++)
			 {
				 s2.ch[p]=s1.ch[i];
				 p++;
			 }
			 for(int nn=0;nn<n;nn++)
			 {    
				 for(int j=0;j<3;j++)
				 {   
					 s2.ch[p]=ss2.ch[j];  
					 p++;  
				 } 
				 
				 for(int kk=(position[nn]-1+ss1.len); kk<position[nn+1]-1;kk++)
				 {   
					 s2.ch[p]=s1.ch[kk];
					 p++;  
				 }
			 }
			 s2.ch[p]='#';
			 s2.len=p;

             for(int qq=0; s2.ch[qq]!='#'; qq++)
					  s1.ch[qq]=s2.ch[qq];
				  s1.ch[qq]='#';
				  s1.len=s2.len ;
				  
		 }
	}
}
           
//
void main()
{
	cout<<"this is a word_editor.\n";
	Str s1;
	Str s2;  

	Str ss;
	Str ss1;
	Str ss2;
	int n;
	s1.input_str();
	int choice=-1;
	while(choice!=0)
	{
		cout<<"choicd for you:\n";
		cout<<"  1:  print the string.\n";
        cout<<"  2:  insert a small string.\n";
	    cout<<"  3:  deletee a small string.\n";
		cout<<"  4:  copy the whole string.\n";
        cout<<"  5:  instead the string.\n";
        cout<<"  6:  find the position of a small string.\n";
		cout<<"  7:  go on inputting. \n";
		cout<<"  0:  over and exit.\n";
		cout<<"your choice :  ";
		cin>>choice;
	
	switch(choice)
	{
	case 1: cout<<"1:  now print the string.\n";
		    s1.print_str(s1);
			break;
    case 2: cout<<"2:  insert a small string.\n";
		    s1.insert_str(s1,s2,ss);
			break;
    case 3: cout<<"3:  deletee a small string.\n";
		    s1.delete_str(s1,s2);
			break;
	case 4: cout<<"4:  copy the whole string.\n";
		    s1.copy_str(s1,s2);
			break;
    case 5: cout<<"5:  insert the string.\n";
		    s1.instead_str(s1,s2,ss1,ss2,n);
			break;
    case 6: cout<<"6:  find the position of a small string.\n";
		    s1.find_position(s1,ss,n);
			break;
	case 7: cout<<"7:  go on inputting.\n";
		    s1.go_on_input(s1);
			break;
    case 0: cout<<"0:  over and exit.\n";
		    cout<<"Goodbye!\n\n";
			break;
	default:cout<<"error.\n";
		    break;
	}
	}
}