hdu 1358 kmp小算法

/*学了一下算法，保存一下*/
#include<cstdio>
#include<iostream>
using namespace std;
int a[1000008],b[10008],next[1000008];
void getnext(int m)
{
    int i=0,j=-1;
    next[0] = -1;
    while(i<m)
    {
        if(j==-1 || b[i] == b[j])
        {
            i++;j++;
            next[i] = j;
        }
        else
            j = next[j];
    }
}
int find(int n,int m)
{
    int i=0,j=0;
    getnext(m);
    while(i<n&&j<m)
    {
        if(j == -1||a[i] ==b[j] )
        {
            i++;j++;
        }
        else
            j = next[j];
    }
    if(j == m)
        return i-m+1;
    return -1;
}
int main()
{
   int n,m;
   int icase;
   cin>>icase;
   while(icase -- )
   {
       scanf("%d%d",&n,&m);
       for(int i=0;i<n;i++)
        scanf("%d",&a[i]);
       for(int i=0;i<m;i++)
        scanf("%d",&b[i]);
        cout<<find(n,m)<<endl;
   }
}