HDUOJ------1711Number Sequence

Number Sequence

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 9114    Accepted Submission(s): 4166

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

 

Source

HDU 2007-Spring Programming Contest

kmp 基础

代码：

 1 /*@kmp扩展@龚细军*/

 2 #include<stdio.h>

 3 #include<string.h>

 4 int aa[1000004],bb[10005];

 5 int next[10005];

 6 //依旧使用next数组

 7 void get_next(int *pt,int len)

 8 {

 9     memset(next,0,sizeof(next));

10     int i=0,j=-1;

11     next[0]=-1;

12     while(i<len)

13     {

14         if(j==-1||pt[i]==pt[j])

15         {

16          ++i;

17          ++j;

18          if(pt[i]!=pt[j])

19              next[i]=j;

20          else

21              next[i]=next[j];

22         }

23         else

24             j=next[j];

25     }

26 }

27 //kmp的扩展

28 int exd_kmp(int *ps,int *pt,int lens,int lent)

29 {

30     int i=-1,j=-1;

31     get_next(pt,lent);

32     while(i<lens)

33     {

34         if(j==-1||ps[i]==pt[j])

35         {

36             ++i;

37             ++j;

38         }

39         else

40             j=next[j];

41      if(j==lent)break;

42     }

43     if(j==lent)

44         return i-j+1;

45     else

46         return -1;

47 }

48 

49 int main()

50 {

51     int test,n,m,i;

52     scanf("%d",&test);

53     while(test--)

54     {

55         scanf("%d%d",&n,&m);

56         for(i=0;i<n;i++)

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

58         for(i=0;i<m;i++)

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

60         printf("%d\n",exd_kmp(aa,bb,n,m));

61     }

62     return 0;

63 }

View Code

 

 java代码：

 1 import java.util.Scanner;

 2 

 3 

 4 public class Main {

 5     

 6     public static void main(String args [])

 7     {  

 8         mt aa = new mt();

 9        Scanner reader =new Scanner(System.in);

10        int test=reader.nextInt();

11        while((test--)>0)

12        {

13           aa.lena=reader.nextInt();

14           aa.lenb=reader.nextInt();

15           aa.init(aa.lena+1, aa.lenb+1);

16           for(int i=0;i<aa.lena;i++)

17             aa.a[i]=reader.nextInt();

18           for(int i=0;i<aa.lenb;i++)

19             aa.b[i]=reader.nextInt();

20              kmp(aa);

21        }

22     }

23     private static void kmp(mt aa)

24     {

25       int i,j;

26       aa.next[i=0]=-1;

27       j=-1;

28       while(i<aa.lenb)

29       {

30         if(j==-1||aa.b[i]==aa.b[j])

31         {

32             i++;

33             j++;

34           if(aa.b[i]==aa.b[j])

35              aa.next[i]=aa.next[j];

36           else 

37              aa.next[i]=j;

38         }

39         else

40             j=aa.next[j];

41       }

42       i=j=0;

43       while(i<aa.lena&&j<aa.lenb)

44       {

45           if(j==-1||aa.a[i]==aa.b[j])

46           {

47              i++;

48              j++;

49           }

50           else    j=aa.next[j];

51       }

52       if(j==aa.lenb)

53           out(i-aa.lenb+1);

54       else

55          out(-1);

56     }

57     private static void out(int aa)

58     {

59         System.out.println(aa);    

60     }

61 }

62 class mt

63 {

64     int [] b,a,next;

65     int  lena,lenb;

66     void init(int lena,int lenb)

67     { 

68            a=new int [lena];

69            b=new int [lenb];

70        next =new int [lenb];

71     }

72 }

View Code