新的开始

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Problem Description

Given two sequences of numbers : a[1], a[2], ...... , a[N], and b[1], b[2], ...... , b[M] (1 <= M <= 10000, 1 <= N <= 1000000). Your task is to find a number K which make a[K] = b[1], a[K + 1] = b[2], ...... , a[K + M - 1] = b[M]. If there are more than one K exist, output the smallest one.

Input

The first line of input is a number T which indicate the number of cases. Each case contains three lines. The first line is two numbers N and M (1 <= M <= 10000, 1 <= N <= 1000000). The second line contains N integers which indicate a[1], a[2], ...... , a[N]. The third line contains M integers which indicate b[1], b[2], ...... , b[M]. All integers are in the range of [-1000000, 1000000].

Output

For each test case, you should output one line which only contain K described above. If no such K exists, output -1 instead.

Sample Input

213 51 2 1 2 3 1 2 3 1 3 2 1 21 2 3 1 313 51 2 1 2 3 1 2 3 1 3 2 1 21 2 3 2 1

Sample Output

6-1

KMP()算法求next[ ]值的确不好理解，下面的三个连接或许可以帮到你：

http://blog.csdn.net/ts173383201/article/details/7850120

http://www.cnblogs.com/dolphin0520/archive/2011/08/24/2151846.html

http://www.56.com/u59/v_NjAwMzA0ODA.html这是严老师的一段视频,看完之后豁然开朗。

#include<stdio.h>#include<string.h>#define max 1000010int a[max],b[10010];int next[10010];int aLen,bLen;void get_next(){    int j,k;    j=0;    k=-1;    next[0]=-1;    while(j<bLen)    {        if(k==-1||b[j]==b[k])          next[++j]=++k;        else          k=next[k];    }}void KMP(){    int i,j=0;    int flag=0;    if(aLen<bLen)    {        printf("-1\n");        return;    }    for(i=0;i<aLen;)//这里i++错误，刚开始思考错了    {        if(a[i]==b[j])        {            if(j==bLen-1)            {                 printf("%d\n",i-bLen+2);                 flag=1;                 break;            }          j++;i++;        }        else        {            j=next[j];            if(j==-1)            {                i++;                j=0;            }        }    }    if(flag==0)    printf("-1\n");}int main(){    int T;    int i,j;    scanf("%d",&T);    while(T--)    {        int k=0;        scanf("%d%d",&aLen,&bLen);        for(i=0; i<aLen; i++)            scanf("%d",&a[i]);        for(j=0; j<bLen; j++)        {              scanf("%d",&b[j]);        }        get_next();        KMP();    }    return 0;}