sicily 1198. Substring

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

13aabac

Sample Output

aabac

题目分析

8个串排出最小字典序

用ab<ba做比较函数排序

#include <iostream>#include <algorithm>bool com(std::string a, std::string b) {  return a+b < b+a;}int main(){  int test;  std::cin >> test;  while (test--) {    int num;    std::cin >> num;    std::string str[num];    for (int i = 0; i < num; ++i)      std::cin >> str[i];    std::sort(str, str+num, com);    for (int i = 0; i < num; ++i)      std::cout << str[i];    std::cout << std::endl;  }}