hdu1711 KMP

    #include <bits/stdc++.h>

    using namespace std;
    const int maxn=1e6+10;
 int  str[maxn],mo[maxn],N,M;
    int Next[maxn];
    void getnext()
    {
        int i=0,j=-1;
        while(i<M)
        {
            if(j==-1||mo[i]==mo[j]){Next[++i]=++j;}
            else j = Next[j];
        }
    }
    int KMP()
    {
        int i=0,j=0;
        int ans=0;
        while(i<N)
        {
            if(j==-1||mo[j]==str[i])i++,j++;
            else j=Next[j];
            if(j==M)return i-M+1;
        }
        return -1;
    }

    int main()
    {
        int t,i;
 scanf("%d",&t);
        while(t--)
        {
        scanf("%d %d",&N,&M);
         for(i=0;i<N;i++)scanf("%d",&str[i]);
         for(i=0;i<M;i++)scanf("%d",&mo[i]);
         if(M>N)printf("-1\n");
         else{

            Next[0]=-1;
            getnext();
         printf("%d\n",KMP());
         }

        }
        return 0;
    }