数据结构-串（字符串）

// my_string.h#ifndef MY_STRING_H#define MY_STRING_H#include <iostream>using namespace std;const int MAXSIZE=100;class MyString{public:    MyString(const MyString& copy);    MyString(const char *init);    MyString();    ~MyString()    {        delete[] m_pstr;    }    int Length() const    {        return m_ncurlen;    }    int Find(MyString part) const;    char* GetBuffer() const;public:    MyString& operator()(int pos, int len);    bool operator==(const MyString cmp_str) const;    bool operator!=(const MyString cmp_str) const;    bool operator<(const MyString cmp_str) const;    bool operator>(const MyString cmp_str) const;    bool operator!() const    {        return (m_ncurlen == 0);    }    MyString& operator=(const MyString &copy);    MyString& operator+=(const MyString &add);    char& operator[](int i);    friend ostream& operator<<(ostream&, MyString&);    friend istream& operator>>(istream&, MyString&);private:    void Next();private:    char *m_pstr;    int m_ncurlen;    int *m_pnext;};#endif // MY_STRING_H

// my_string.cpp#include "my_string.h"#include <cstring>#include <iostream>using std::cout;using std::endl;MyString::MyString(){    m_pstr = new char[MAXSIZE];    if(!m_pstr)    {        cerr << "Allocation Error" << endl;        exit(1);    }    this->m_ncurlen = 0;    m_pstr[0] = '\0';}MyString::MyString(const char *init){    m_pstr = new char[MAXSIZE+1];    if(!m_pstr)    {        cerr << "Allocation Error" << endl;        exit(1);    }    this->m_ncurlen = strlen(init);    strcpy(m_pstr, init);}MyString::MyString(const MyString &copy){    m_pstr = new char[MAXSIZE];    if(!m_pstr)    {        cerr << "Allocation Error" << endl;        exit(1);    }    this->m_ncurlen = copy.m_ncurlen;    strcpy(m_pstr, copy.m_pstr);}int MyString::Find(MyString part) const{    int posP = 0, posT = 0;    int lengthP = part.m_ncurlen, lengthT = this->m_ncurlen;    part.Next();    while(posP < lengthP && posT < lengthT)    {        if(part.m_pstr[posP] == this->m_pstr[posT])        {            posP++;            posT++;        }        else        {            if(posP == 0)            {                posT++;            }            else            {                posP = part.m_pnext[posP-1];            }        }    }    delete[] part.m_pnext;    if(posP < lengthP)    {        return 0;    }    else    {        return 1;    }}void MyString::Next(){    int length = this->m_ncurlen;    this->m_pnext = new int[length];    this->m_pnext[0] = 0;    for(int i = 1; i < length; i++)    {        int j = this->m_pnext[i-1];        while(*(this->m_pstr+1) != *(this->m_pstr+j) && j > 0)        {            j = this->m_pnext[j-1];        }        if(*(this->m_pstr+i) == *(this->m_pstr+j))        {            this->m_pnext[i] = j + 1;        }        else        {            this->m_pnext[i] = 0;        }    }}char *MyString::GetBuffer() const{    return this->m_pstr;}MyString& MyString::operator()(int pos, int len){    MyString *temp = new MyString;    if(pos < 0 || pos + len - 1 > MAXSIZE || len < 0)    {        temp->m_ncurlen = 0;        temp->m_pstr[0] = '\0';    }    else    {        if(pos+len-1 >= m_ncurlen)        {            len = m_ncurlen - pos;        }        temp->m_ncurlen = len;        for(int i = 0, j = pos; i < len; i++, j++)        {            temp->m_pstr[i] = m_pstr[j];        }        temp->m_pstr[len] = '\0';    }    return *temp;}bool MyString::operator==(const MyString cmp_str) const{    if(this->m_ncurlen != cmp_str.m_ncurlen)    {        return 0;    }    for(int i = 0; i < this->m_ncurlen; i++)    {        if(this->m_pstr[i] != cmp_str.m_pstr[i])        {            return 0;        }    }    return 1;}bool MyString::operator!=(const MyString cmp_str) const{    if(*this == cmp_str)    {        return 0;    }    return 1;}bool MyString::operator<(const MyString cmp_str) const{    if(this->m_ncurlen != cmp_str.m_ncurlen)    {        return this->m_ncurlen < cmp_str.m_ncurlen;    }    for(int i = 0; i < this->m_ncurlen; i++)    {        if(this->m_pstr[i] != cmp_str.m_pstr[i])        {            return this->m_pnext[i] < cmp_str.m_pnext[i];        }    }}bool MyString::operator>(const MyString cmp_str) const{    if(*this < cmp_str || *this==cmp_str)    {        return 0;    }    return 1;}MyString& MyString::operator=(const MyString &copy){    delete[] this->m_pstr;    this->m_pstr = new char[copy.m_ncurlen];    strcpy(this->m_pstr, copy.m_pstr);    return (*this);}MyString& MyString::operator+=(const MyString &add){    int length = this->m_ncurlen + add.m_ncurlen;    int n = this->m_ncurlen;    MyString temp(*this);    delete[] this->m_pstr;    this->m_pstr = new char[length+1];    for(int i = 0; i < n; i++)    {        this->m_pstr[i] = temp[i];    }    for(int i = n; i < length; i++)    {        this->m_pstr[i] = add.m_pstr[i-n];    }    this->m_pstr[length] = '\0';    return (*this);}char& MyString::operator[](int i){    if(i<0 || i >= this->m_ncurlen)    {        cout << __FUNCTION__ << " error : out of boundary! " << endl;        exit(1);    }    return this->m_pstr[i];}ostream& operator<<(ostream& os, MyString& str){    os << str.m_pstr;    return os;}istream& operator>>(istream& is, MyString& str){    is >> str.m_pstr;    return is;}

// main.cpp#include <iostream>#include "my_string.h"using namespace std;int main(int argc, char *argv[]){    MyString test1("babc");    MyString test2("abababcdefb");    cout << test2.Find(test1) << endl;    cout << test2(2, 3) << endl;    if(test1 < test2)    {        cout << test1 << " < " << test2 << endl;    }    else    {        if(test1 == test2)        {            cout << test1 << " == " << test2 << endl;        }        else        {            if(test1 > test2)            {                cout << test1 << " > " << test2 << endl;            }        }    }    int length = test2.Length();    for(int i = 0; i < length; i++)    {        cout << test2[i];    }    cout << endl;    test1 += test2;    cout << test1 << endl;    test1 = test2;    cout << test1 << endl;    return 0;}