KMP算法

/*
KMP算法：假设a[]是主串，b[]是模式串
*/
#include<iostream>
using namespace std ;
int next[1002] ;
void get_next(char a[])
{
	int i = 0 , j = -1 ,lena = strlen(a);
	next[0] = -1;
	while( i < lena)
	{
		if( j == -1 || a[i]  == a[j])
		{
			i ++ ;
			j ++;
			next[i] = j ;
		}
		else
			j = next[j] ;
	}
	return ;
}

bool KMP(char a[],char b[])
{
	int i = 0 , j = 0;
	int lena = strlen(a),lenb = strlen(b) ;
	while(i < lena)
	{
		if( j == -1 || a[i]  == b[j])
		{
			i ++;
			j ++ ;
		}
		else
			j = next[j] ;
		if(j>=lenb)
			return true ;
	}
	return false;
}
int main(void)
{
	char a[102] , b[102] ;
	while(cin >> a>> b)
	{
		get_next(b);
		if(KMP(a,b))
			cout<<"匹配成功"<<endl;
		else
			cout<<"匹配失败"<<endl;
	}
	return 0 ;
}