KMP算法的代码实现一

//kmp.h

#ifndef KMP_H
#define KMP_H
#include <iostream>
using namespace std;
const  int Maxsize=50;
class Char
{
public:
	Char(char a[],int longth);	
	void print();
	void printnext();
	void GetNext(char T[]);
private:
	char T[Maxsize];
	int next[Maxsize];
	int longth;
};
void Char::print()
{
	cout<<"字符串为："<<endl;
	for(int i=0;i<longth;i++)
		cout<<T[i];
	cout<<endl;
}
Char::Char(char a[],int longth)
{
	this->longth=longth;
	for(int i=0;i<longth;i++)
		T[i]=a[i];
	T[longth]='\0';
}
void Char::GetNext(char T[])
{
	int k=0,i=-1;
	this->next[0]=-1;
	while(k<longth-1)
	{
		if(i==-1||T[i]==T[k])
		{
			++i;
			++k;
			 next[k]=i;
		}
		else
			i=next[i];
	}
	next[longth]='\0';
}
void Char::printnext()
{
	cout<<"next[j]为："<<endl;
	for(int i=0;i<longth;i++)
		cout<<"next["<<i<<"]="<<next[i]<<endl;
}

#endif

//next.cpp

#include "kmp.h"
void main()
{
	int longth=0;
	cout<<"请输入长度（最长为50）:";
	cin>>longth;
	while(longth>Maxsize)
	{
		cout<<"请重新输入：";
		cin>>longth;
	}
	char*a=new char[longth];    //一开始忘了申请长度为longth的空间
	cout<<"请输入字符串：\n"<<endl;
	for(int i=0;i<longth;i++)
	{
		cout<<"第"<<i+1<<"个字符为：";
		cin>>a[i];
	}
	Char c(a,longth);
	c.print();
	c.GetNext(a);
	c.printnext();
	delete []a;
}

注：

void Char::GetNext(char T[])

KMP算法 ，我是参照了《大话数据结构》这本书。