搜索 J - 10

Description

A common pastime for poker players at a poker table is to shuffle stacks of chips. Shuffling chips is performed by starting with two stacks of poker chips, S₁ and S₂, each stack containing C chips. Each stack may contain chips of several different colors.

The actual shuffle operation is performed by interleaving a chip from S₁ with a chip from S₂ as shown below for C = 5:

The single resultant stack, S₁₂, contains 2 * C chips. The bottommost chip of S₁₂ is the bottommost chip from S₂. On top of that chip, is the bottommost chip from S₁. The interleaving process continues taking the 2^nd chip from the bottom of S₂ and placing that on S₁₂, followed by the 2^nd chip from the bottom of S₁ and so on until the topmost chip from S₁ is placed on top of S₁₂.

After the shuffle operation, S₁₂ is split into 2 new stacks by taking the bottommost C chips from S₁₂ to form a new S₁ and the topmost C chips from S₁₂ to form a new S₂. The shuffle operation may then be repeated to form a new S₁₂.

For this problem, you will write a program to determine if a particular resultant stack S₁₂ can be formed by shuffling two stacks some number of times.

Input

The first line of input contains a single integer N, (1 ≤ N ≤ 1000) which is the number of datasets that follow.

Each dataset consists of four lines of input. The first line of a dataset specifies an integer C, (1 ≤ C ≤ 100) which is the number of chips in each initial stack (S₁ and S₂). The second line of each dataset specifies the colors of each of the C chips in stack S₁, starting with the bottommost chip. The third line of each dataset specifies the colors of each of the C chips in stack S₂ starting with the bottommost chip. Colors are expressed as a single uppercase letter (A through H). There are no blanks or separators between the chip colors. The fourth line of each dataset contains 2 * Cuppercase letters (A through H), representing the colors of the desired result of the shuffling of S₁ and S₂ zero or more times. The bottommost chip’s color is specified first.

Output

Output for each dataset consists of a single line that displays the dataset number (1 though N), a space, and an integer value which is the minimum number of shuffle operations required to get the desired resultant stack. If the desired result can not be reached using the input for the dataset, display the value negative 1 (−1) for the number of shuffle operations.

Sample Input

2
4
AHAH
HAHA
HHAAAAHH
3
CDE
CDE
EEDDCC

Sample Output

1 2
2 -1

           这到题的基本题意为给你两堆已知序列的扑克牌，在给你一堆要求顺序扑克牌，问这两堆扑克牌交叉洗牌能否产生要求序列的扑克牌，若可能生成的话，则输出最小的操作数，如果不可以的话，则输出-1。

         这道题为一道BFS，每次洗牌有两张情况，将每次洗牌的两种情况分别与要求的序列比较，直到产生要求

的队列或循环到原来的两堆扑克牌为止。

源代码如下：

#include<iostream>
#include<stdio.h>  
#include<string.h>  
const int MAXN=110;  
int search();  
char s1[MAXN],s2[MAXN],s12[MAXN+MAXN];  
int tot,c,c12;  
int main()  
{  

    int i,n;  
    scanf("%d",&n);  
    for(i=1;i<=n;i++)  
    {  
        scanf("%d",&c);  
        scanf("%s%s%s",s1,s2,s12);  
  
        c12=2*c;  
        tot=search();  
  
        printf("%d %d\n",i,tot?tot:-1);  
    }  
    return 0;  
}  
  
int search()  
{  
    tot=0;  
    int i,j,k;  
    char s1t[MAXN],s2t[MAXN],s12t[MAXN+MAXN];  
    strcpy(s1t,s1),strcpy(s2t,s2);  
    while(1)  
    {  
        for(i=0,j=0,k=0;k<c12;k++)
		{    
            if(k%2)s12t[k]=s1t[j++];  
            else s12t[k]=s2t[i++];  
        }  
        s12t[k]='\0';  
        tot++;  
        if(!strcmp(s12,s12t))return tot;   
        for(i=0;i<c;i++)   
            s1t[i]=s12t[i];  
        s1t[i]='\0';  
        for(i=0;i<c;i++)   
            s2t[i]=s12t[i+c];  
        s2t[i]='\0';  
        if(!strcmp(s1,s1t)&&(!strcmp(s2,s2t)))return 0;
	}
    return 0;   
}