文字列大好きいろはちゃんイージー / Iroha Loves Strings (ABC Edition) AtCoder - 1978

文字列大好きいろはちゃんイージー / Iroha Loves Strings (ABC Edition)

 AtCoder - 1978 

Problem Statement

 

Iroha has a sequence of N strings S₁,S₂,…,S_N. The length of each string is L.

She will concatenate all of the strings in some order, to produce a long string.

Among all strings that she can produce in this way, find the lexicographically smallest one.

Here, a string s=s₁s₂s₃...s_n is lexicographically smaller than another string t=t₁t₂t₃...t_m if and only if one of the following holds:

• There exists an index i(1≦i≦min(n,m)), such that s_j=t_j for all indices j(1≦j<i), and s_i<t_i.
• s_i=t_i for all integers i(1≦i≦min(n,m)), and n<m.

Constraints

 

• 1≦N,L≦100
• For each i, the length of S_i equals L.
• For each i, S_i consists of lowercase letters.

Input

 

The input is given from Standard Input in the following format:

N L
S1
S2
:
SN

Output

 

Print the lexicographically smallest string that Iroha can produce.

Sample Input 1

 

3 3
dxx
axx
cxx

Sample Output 1

 

axxcxxdxx

The following order should be used: axx, cxx, dxx.

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cmath>
#include<utility>
#include<set>
#include<vector>
#include<map>
#include<queue>
#include<stack>
#define maxn 1010
#define INF 0x3f3f3f3f
#define LL long long
#define ULL unsigned long long
#define E 1e-8
#define mod 1000000007
#define P pair<int,int>
using namespace std;
//n个  长度是L
int main()
{
    int n,l;
    while(cin>>n>>l)
    {
        string s[105];
        int a[105];
        for(int i = 0 ; i < n ; i++ )
        {
            cin>>s[i];
            a[i] = (int)s[i][0];
            //cout<<a[i]<<endl;
        }
        sort(s+0,s+n);
        for(int j = 0 ; j < n ; j++ )
        cout<<s[j];
        }
}