hdu 3080 (KMP + 매 거 진)

Blue Jeans
Time Limit: 1000MS
 
Memory Limit: 65536K
Total Submissions: 10119
 
Accepted: 4280
Description
The Genographic Project is a research partnership between IBM and The National Geographic Society that is analyzing DNA from hundreds of thousands of contributors to map how the Earth was populated.
As an IBM researcher, you have been tasked with writing a program that will find commonalities amongst given snippets of DNA that can be correlated with individual survey information to identify new genetic markers.
A DNA base sequence is noted by listing the nitrogen bases in the order in which they are found in the molecule. There are four bases: adenine (A), thymine (T), guanine (G), and cytosine (C). A 6-base DNA sequence could be represented as TAGACC.
Given a set of DNA base sequences, determine the longest series of bases that occurs in all of the sequences.
Input
Input to this problem will begin with a line containing a single integer n indicating the number of datasets. Each dataset consists of the following components:

A single positive integer m (2 <= m <= 10) indicating the number of base sequences in this dataset.

m lines each containing a single base sequence consisting of 60 bases.

Output
For each dataset in the input, output the longest base subsequence common to all of the given base sequences. If the longest common subsequence is less than three bases in length, display the string "no significant commonalities" instead. If multiple subsequences of the same longest length exist, output only the subsequence that comes first in alphabetical order.
Sample Input

3
2
GATACCAGATACCAGATACCAGATACCAGATACCAGATACCAGATACCAGATACCAGATA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
3
GATACCAGATACCAGATACCAGATACCAGATACCAGATACCAGATACCAGATACCAGATA
GATACTAGATACTAGATACTAGATACTAAAGGAAAGGGAAAAGGGGAAAAAGGGGGAAAA
GATACCAGATACCAGATACCAGATACCAAAGGAAAGGGAAAAGGGGAAAAAGGGGGAAAA
3
CATCATCATCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
ACATCATCATAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AACATCATCATTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT

Sample Output

no significant commonalities
AGATAC
CATCATCAT

Source
South Central USA 2006
 
HDU 2328
이 문 제 는 여러 문자열 의 가장 긴 공통 문자열 을 요구 합 니 다.
가장 긴 공통 문자열 을 구 하 는 것 은 흔히 볼 수 있 는 알고리즘 이다.그러나 이 문 제 는 흔 한 두 문자열 의 DP 방법 을 제외 한 여러 문자열 을 원 합 니 다.
접미사 배열 을 사용 할 수 있 지만, 나 는 방금 접미사 배열 을 접 했 기 때문에 유연 하 게 사용 할 수 없다.
KMP + 매 거 를 시도 해 보 았 지만 시간 을 초과 하지 않 았 습 니 다.
가장 짧 은 문자열 을 찾 아 이 문자열 의 하위 문자열 을 매 거 진 다음 각각 다른 문자열 과 KMP 를 만 들 고 길이 가 가장 길 고 길이 가 같은 경우 사전 순서 가 가장 작은 공공 하위 문자열 을 찾 습 니 다.

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;

const int MAXN=60+10;
char str[10+10][MAXN];
int next[MAXN];

//KMP     next[]  
void getNext(char *p)
{
    int j,k,len=strlen(p);
    j=0;
    k=-1;
    next[0]=-1;
    while(j<len)
    {
        if(k==-1||p[j]==p[k])
        {
            next[++j]=++k;
        }
        else k=next[k];
    }
}


//     T   S        
//       0   ,       -1。
int KMP_Index(char *W,char *T)
{
    int i=0, j=0,wlen=strlen(W),tlen=strlen(T);
    getNext(W);
    while(i<tlen&&j<wlen)
    {
        if(j==-1||T[i]==W[j])
        {
            i++; j++;
        }
        else
            j=next[j];
    }
    if(j==wlen)
        return i-wlen;
    else
        return -1;
}


int main()
{
	int cas,n,i,j,k,Minlen,Minid;
	char tmp[MAXN],ans[MAXN];
	bool flag;
	cin>>cas;
	while(cas--)
	{
		scanf("%d",&n);
		scanf("%s",str[0]);
		Minlen=strlen(str[0]);
		flag=false;
		for(i=1;i<n;i++)
		{
			scanf("%s",str[i]);
			Minid=0;
			if(strlen(str[i])<Minlen)
			{
				Minid=i;Minlen=strlen(str[i]);
			}
		}
	//	printf("str[Minid]=%s
",str[Minid]);

		ans[0]=0;
		for(i=Minlen;i>=0;i--)
		{
			for(j=0;j<=Minlen-i;j++)
			{
				strncpy(tmp,str[Minid]+j,i);
				tmp[i]=0;
			//	printf("tmp=%s
",tmp);
				
				for(k=0;k<n;k++)
				{
					if(k!=Minid)
					{
						if(KMP_Index(tmp,str[k])==-1)
							break;
					}
				}
				
				if(k==n)
				{
					if(strlen(ans)<i)
						strcpy(ans,tmp);
					else if(strlen(ans)==i&&strcmp(ans,tmp)>0)
						strcpy(ans,tmp);
					flag=true;
				}
			}
			//if(flag)break;
		}
	if(strlen(ans)<3)
		printf("no significant commonalities
");
	else printf("%s
",ans);
	}
	return  0;
}