HDU——T 1711 Number Sequence

Posted 2020-10-02

http://acm.hdu.edu.cn/showproblem.php?pid=1711

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 29129    Accepted Submission(s): 12254

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

2 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

6 -1

 

模板练习题

 1 #include <algorithm>
 2 #include <cstdio>
 3 
 4 using namespace std;
 5 
 6 const int N(1000000+5);
 7 const int M(10000+626);
 8 int l1,l2,a[N],b[N],p[N];
 9 
10 inline void Get_next()
11 {
12     for(int j=0,i=2;i<=l2;i++)
13     {
14         if(j>0&&b[i]!=b[j+1]) j=p[j];
15         if(b[i]==b[j+1]) j++;
16         p[i]=j;
17     }
18 }
19 inline void kmp()
20 {
21     for(int j=0,i=1;i<=l1;i++)
22     {
23         if(j>0&&a[i]!=b[j+1]) j=p[j];
24         if(a[i]==b[j+1]) j++;
25         if(j==l2)
26         {
27             printf("%d\n",i-j+1);
28             return ;
29         }
30     }
31     puts("-1");
32 }
33 
34 int main()
35 {
36     int t;scanf("%d",&t);
37     for(;t--;)
38     {
39         scanf("%d%d",&l1,&l2);
40         for(int i=1;i<=l1;i++) scanf("%d",a+i);
41         for(int i=1;i<=l2;i++) scanf("%d",b+i);
42         Get_next();
43         kmp();
44     }
45     return 0;
46 }