HDU 1711 Number Sequence

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Number Sequence

Time Limit: 5000MS Memory Limit: 32768KB 64bit IO Format: %I64d & %I64u

Submit Status

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

思路：裸KMP

<span style="font-size:18px;">#include <iostream>#include <algorithm>#include <cstdio>#include <cstring>#include <queue>#include <stack>#include <set>#include <vector>#include<cstdlib>#include <cmath>#pragma comment (linker,"/STACK:102400000,102400000")using namespace std;#define maxn 1000500int next_[maxn];int  str1[maxn];int  str2[maxn];int len_1,len_2;int conut;void get_next(){    int i=0;    int j=-1;    next_[i]=j;    while(i<len_2)    {        if(j==-1 || str2[i]==str2[j])        {            ++i;            ++j;            next_[i]=j;        }        else            j=next_[j];    }}void kmp(){    get_next();    int i=0;    int j=0;    int len=len_1;    while(i<len)    {        if(j==-1 || str1[i]==str2[j])        {            ++i;            ++j;        }        else            j=next_[j];        if(j==len_2)        {            cout<<i-len_2+1<<endl;            return;        }    }    cout<<"-1"<<endl;}int main(){    int T;    cin>>T;    while(T--)    {         scanf("%d%d",&len_1,&len_2);        memset(next_,-1,sizeof(next_));        conut=0;        for(int i=0;i<len_1;i++) scanf("%d",&str1[i]);        for(int i=0;i<len_2;i++) scanf("%d",&str2[i]);        kmp();        //cout<<conut<<endl;    }    return 0;}</span>

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