#include<stdio.h>
#include <iostream.h>
class string{
public:
	string();
	string(char);
	string(unsigned);
	string(const char*);
	string(const string&);
	~string();
	friend class substring;
	void operator=(const string &right);
	void operator +=(const string&right);
friend	string operator +(const string &left,
						  const string &right);
	substring operator ()(unsigned start ,unsigned len);
	istream&getline(istream&);
	unsigned length()const;
	char&operator [](unsigned index)const;
	int compare(const string&)const;
	operator const char*()const;
private:
	unsigned buflen;
	char* buffer;
};

class substring{
public:
	substring (string &base,unsigned start,unsigned len);
	substring (const substring &source);
	void operator=(const string &)const;
	operator string ()const ;
private:
	string &base;
	const unsigned start;
	const unsigned len;
};
//
class stringMatcher{
public:
	stringMatcher(string&t);
	virtual int init();
	int operator !()const;
	virtual int operator++()=0;
	substring operator()();
	unsigned position ()const;
 void position (unsigned p);
	unsigned length();
protected:
	string &text;
	int pos;
	unsigned patlen;
};
//
class KMPStrMatcher:public stringMatcher{
public:
	 KMPStrMatcher(const string&p,string&t);
	~ KMPStrMatcher();
    virtual	int operator++();
private:
const  string &pattern;
	int *prefix;
};