数据结构_串_串的一些操作_C++实现

#include<iostream>
#include<string>
using namespace std;

class STRING
{
public:
STRING();
void GetString();
void GetSubString();
void Index();
void Print();
private:
void Index1();
void Index2();
bool Match(int);
string str;
string sub;
int strlen;
int sublen;
int pos;
};

STRING::STRING()
{
str.clear();sub.clear();
pos=strlen=sublen=0;
}

void STRING::GetString()
{
cout<<"Please Input The MainString :"<<endl<<endl;
cin>>str;
strlen=str.length();
}

void STRING::GetSubString()
{
cout<<"Please Input The SubString :"<<endl<<endl;
cin>>sub;
sublen=sub.length();
}

void STRING::Index()
{
cout<<"Index Called !"<<endl<<endl;
cout<<"Which Position Do You Want To Start Your Index ?"<<endl<<endl;
cin>>pos;
pos--;
cout<<"Which Method Do You Want To Use ?"<<endl<<endl;
cout<<"1 . Simple Method ."<<endl
<<"2 . Improvement Method ."<<endl<<endl;
char choice;
cin>>choice;
switch(choice)
{
case '1':
Index1();
break;
case '2':
Index2();
break;
default:
cout<<"No Such Method !"<<endl<<endl;
break;
}
}

void STRING::Index1()
{
cout<<"Simple Method Called !"<<endl<<endl;
if(pos>strlen-sublen)
{
cout<<"Failed !"<<endl<<endl;
return;
}
int i,j;
i=pos;
j=0;
while(i<strlen&&j<sublen)
{
if(str[i]==sub[j])
{
i++;
j++;
}
else
{
i=i-j+1;
j=0;
}
}
if(j==sublen)
{
cout<<"Succed ! "<<" Position = "<<i-j+1<<endl<<endl;
}
else
{
cout<<"Failed !"<<endl<<endl;
}
}

void STRING::Index2()
{
cout<<"ImproveMent Method Called !"<<endl<<endl;
int i,j;
i=pos;
j=0;
while(i<=strlen-sublen&&j<sublen)
{
if(str[i]==sub[j]&&str[i+sublen-1]==sub[sublen-1]&&Match(i))
{
cout<<"Succed ! "<<" Position = "<<i-j+1<<endl<<endl;
return;
}
else
{
i++;
j=0;
}
}
cout<<"Failed !"<<endl<<endl;
}

void STRING::Print()
{
cout<<"Main String = "<<str<<endl<<" Length = "<<strlen<<endl;
cout<<"SubString = "<<sub<<endl<<" Length = "<<sublen<<endl<<endl;
}

bool STRING::Match(int i)
{
for(int j=0;j<sublen;j++)
{
if(str[i+j]!=sub[j])
return false;
}
return true;
}

#include<iostream>
#include"head.h"
using namespace std;

int main()
{
STRING str;
char choice;
while(1)
{
cout<<"Your Choice Please ?"<<endl<<endl
<<"1 . Set Main String"<<endl
<<"2 . Set SubString"<<endl
<<"3 . Index"<<endl
<<"4 . Print"<<endl
<<"5 . Quit"<<endl<<endl;
cin>>choice;
switch(choice)
{
case '1':
str.GetString();
break;
case '2':
str.GetSubString();
break;
case '3':
str.Index();
break;
case '4':
str.Print();
break;
case '5':
return 0;
default:
cout<<"No Such Choice !"<<endl;
break;
}
}
}