1198.Substring

Constraints

Time Limit: 1 secs, Memory Limit: 32 MB

Description

 

Dr lee cuts a string S into N pieces,s[1],…,s[N].   

Now, Dr lee gives you these N sub-strings: s[1],…s[N]. There might be several possibilities that the string S could be. For example, if Dr. lee gives you three sub-strings {“a”,“ab”,”ac”}, the string S could be “aabac”,”aacab”,”abaac”,…   

Your task is to output the lexicographically smallest S. 

 

Input

 

        The first line of the input is a positive integer T. T is the number of the test cases followed.   

The first line of each test case is a positive integer N (1 <=N<= 8 ) which represents the number of sub-strings. After that, N lines followed. The i-th line is the i-th sub-string s[i]. Assume that the length of each sub-string is positive and less than 100. 

 

Output

 

The output of each test is the lexicographically smallest S. No redundant spaces are needed. 

 

Sample Input

1
3
a
ab
ac

Sample Output

aabac

Problem Source

ZSUACM Team Member

tips:对于每两个字符串，就两种排序方式，比较其字典序即可，利用sort

#include

07. #include

08. #include

09. using namespace std;

10. int cmp(string a, string b)

11. {

12. /*

13. int a_len,b_len;

14. a_len=(int)a.size();

15. b_len=(int)b.size();

16. if (a_len>b_len)

17. {

18. for (int n=0;n

19. if (a==b) return 1;

20. }

21. else if (b_len>a_len)

22. {

23. for (int n=0;n

24. if (a==b) return 0;

25. }

26. */

27. return a+b

28. }

29. int input[1050];

30. int main()

31. {

32. int t;

33. scanf("%d",&t);

34. while (t--)

35. {

36. int N;

37. string tmp[10];

38. scanf("%d",&N);

39. for (int n=0;n> tmp[n];

40. sort(tmp,tmp+N,cmp);

41. string answer;

42. for (int n=0;n

43. cout << answer << endl;

44. }

45. return 0;

46. }