Number Sequence

Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 17971 Accepted Submission(s): 7854

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

13 5

1 2 1 2 3 1 2 3 1 3 2 1 2

1 2 3 1 3

13 5

1 2 1 2 3 1 2 3 1 3 2 1 2

1 2 3 2 1

Sample Output

-1

#include<cstdio>

#include<cstring>

using namespace std;

const int MAXN=;

int a[MAXN],b[MAXN],next[MAXN];

int lena,lenb;

void getnext()

{

    int i=,j=-;

    next[]=-;

    while(i<lenb)

    {

        if(j==-||b[i]==b[j])

        {

            i++;

            j++;

            next[i]=j;

        }

        else    j=next[j];

    }

}

int KMP()

{

    getnext();

    int i=,j=;

    while(i<lena&&j<lenb)

    {

        if(j==-||a[i]==b[j])

        {

            i++;

            j++;

        }

        else    j=next[j];

    }

    if(j==lenb)    return i-j+;

    else    return -;

}

int main()

{

   int T;

   scanf("%d",&T);

   while(T--)

   {

           memset(next,,sizeof(next));

           scanf("%d%d",&lena,&lenb);

           for(int i=;i<lena;i++)

               scanf("%d",&a[i]);

           for(int i=;i<lenb;i++)

               scanf("%d",&b[i]);

           printf("%d\n",KMP());

   }

    return ;

}

巴特西

HDU1711(KMP入门题)

Number Sequence

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