杭电1503 LCS+字符串合并

Advanced Fruits

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 2998    Accepted Submission(s): 1534
Special Judge

Problem Description

The company "21st Century Fruits" has specialized in creating new sorts of fruits by transferring genes from one fruit into the genome of another one. Most times this method doesn't work, but sometimes, in very rare cases, a new fruit emerges that tastes like a mixture between both of them.
A big topic of discussion inside the company is "How should the new creations be called?" A mixture between an apple and a pear could be called an apple-pear, of course, but this doesn't sound very interesting. The boss finally decides to use the shortest string that contains both names of the original fruits as sub-strings as the new name. For instance, "applear" contains "apple" and "pear" (APPLEar and apPlEAR), and there is no shorter string that has the same property.

A combination of a cranberry and a boysenberry would therefore be called a "boysecranberry" or a "craboysenberry", for example.

Your job is to write a program that computes such a shortest name for a combination of two given fruits. Your algorithm should be efficient, otherwise it is unlikely that it will execute in the alloted time for long fruit names.

 

Input

Each line of the input contains two strings that represent the names of the fruits that should be combined. All names have a maximum length of 100 and only consist of alphabetic characters.

Input is terminated by end of file.

 

Output

For each test case, output the shortest name of the resulting fruit on one line. If more than one shortest name is possible, any one is acceptable.

 

Sample Input

apple peachananas bananapear peach

 

Sample Output

appleachbananaspearch

 

题意：给出两个字符串，要求合并，但公共子串部分只输出一次。

思路：找出两个串的LCS，存在第三个串中，然后按序依次输出三个串中需要输出的部分。输出时比较难处理，第三个串S3用结构体存储，结构体还包括i,j分别代表公共子串各字符在S1串和S2串的位置。

AC代码：

/*不能保证所述全部正确，如有不足之处，还请前辈指出*/#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;char s1[1005],s2[1005];int dp[1005][1005];struct ss{    int i,j;    char c;}s3[1005];int main(){   // freopen("D://in.txt","r",stdin);    int l1,l2,k=0;    while(~scanf("%s %s",s1,s2))    {        l1=strlen(s1);        l2=strlen(s2);        memset(dp,0,sizeof(dp));        for(int i=1;i<=l1;i++)        {            for(int j=1;j<=l2;j++)            {                if(s1[i-1]==s2[j-1])                    dp[i][j]=dp[i-1][j-1]+1;                else                    dp[i][j]=max(dp[i][j-1],dp[i-1][j]);            }        }        k=0;        for(int i=l1,j=l2;i>=1&&j>=1;)        {            if(s1[i-1]==s2[j-1])            {                s3[k].c=s1[i-1];                s3[k].i=i-1;                s3[k].j=j-1;                i--;                j--;                k++;            }            else if(dp[i][j-1]>dp[i-1][j])                j--;            else                i--;        }        int i=0,j=0;        for(k--;k>=0;--k)        {            for(;s3[k].i!=i;i++)                printf("%c",s1[i]);            for(;s3[k].j!=j;j++)                printf("%c",s2[j]);            printf("%c",s3[k].c);            ++i,++j;        }        for(;s1[i]!='\0';i++)            printf("%c",s1[i]);        for(;s2[j]!='\0';j++)            printf("%c",s2[j]);        printf("\n");    }    return 0;}