Studious Student

1StudiousStudentWrong.java

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Scanner;

public class StudiousStudentWrong {

	public static void main(String[] args) throws Exception {

		System.setIn(new FileInputStream("studious_student.in"));
		System.setOut(new PrintStream(new FileOutputStream("studious_student.first_try")));

		try (Scanner in = new Scanner(System.in)) {
			int tests = in.nextInt();
			in.nextLine();

			for (long test = 1; test <= tests; test++) {
				in.nextInt();
				String[] str = in.nextLine().split(" ");
				Arrays.sort(str);
				for (String s : str) {
					System.out.print(s);
				}
				System.out.println();
			}
		}
	}
}

2StudiousStudent.java

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class StudiousStudent {

	public static void main(String[] args) throws Exception {

		System.setIn(new FileInputStream("studious_student.in"));
		System.setOut(new PrintStream(new FileOutputStream("studious_student.good")));

		try (Scanner in = new Scanner(System.in)) {
			int tests = in.nextInt();
			in.nextLine();

			for (long test = 1; test <= tests; test++) {
				in.nextInt();
				String[] str = in.nextLine().split(" ");
				Comparator<String> comparator = new Comparator<String>() {
					@Override
					public int compare(String a, String b) {
						return (a + b).compareTo(b + a);
					}
				};
				Arrays.sort(str, comparator);
				for (String s : str) {
					System.out.print(s);
				}
				System.out.println();
			}
		}
	}
}

3StudiousStudent8.java

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Scanner;
import java.util.stream.Collectors;

public class StudiousStudent8 {

	public static void main(String[] args) throws Exception {

		System.setIn(new FileInputStream("studious_student.in"));
		System.setOut(new PrintStream(new FileOutputStream("studious_student.good")));

		try (Scanner in = new Scanner(System.in)) {
			int tests = in.nextInt();
			in.nextLine();

			for (long test = 1; test <= tests; test++) {
				in.nextInt();
				System.out.println(Arrays.stream(in.nextLine().split(" ")).
					sorted((a, b) -> (a + b).compareTo(b + a)).
					collect(Collectors.joining("")));
			}
		}
	}
}

4StudiousStudent.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Kata
{   class StudiousStudent
    {
        static void Main(string[] args) {
            const string filename = @"..\..\studious_prod";
            using (var input = File.OpenText(filename + ".in"))
            using (var output = File.CreateText(filename + ".out")) {
                new StudiousStudent().Process(input, output);
            }
        }

        private static IComparer<string> comparer = Comparer<string>.Create(
            (a, b) => (a+b).CompareTo(b+a));

        public void Process(TextReader input, TextWriter output)
        {
            int tests = int.Parse(input.ReadLine());
            for (var test = 0; test < tests; test++) {
                output.WriteLine(String.Join("", input.ReadLine().Split().Skip(1).OrderBy(n => n, comparer)));
            }
        }

    }

}

5studious_student.cpp

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

bool comparer(const string &a, const string &b) { return a+b < b+a; }

void main() 
{
	freopen("studious_student.in", "rt", stdin);
	freopen("studious_student.out", "wt", stdout);

	int N,M;
	string words[10];
	
	cin >> N;
	for (auto test = 0; test < N; test++)  {
		cin >> M;
		for (auto i = 0; i < M; i++)
			cin >> words[i];
		sort(words, words + M, comparer);

		for (auto i = 0; i < M; i++)
			cout << words[i];
		cout << endl;
	}
}

6studious_student_lamdas.cpp

#include <iostream>
#include <string>
#include <algorithm>
#include <functional>

using namespace std;

void main() 
{
	freopen("studious_student.in", "rt", stdin);
	freopen("studious_student.out", "wt", stdout);

	int N,M;
	string w[10];
	
	cin >> N;
	for (auto test = 0; test < N; test++)  {
		cin >> M;
		for (auto i = 0; i < M; i++)
			cin >> w[i];
		sort(w, w + M, [](const string& a, const string& b) { return a+b < b+a; });

		for (auto i = 0; i < M; i++)
			cout << w[i];
		cout << endl;
	}
}

7studious_student.py

#! /usr/bin/env python2

FILENAME = "example"
import sys
sys.stdin = open(FILENAME + ".in", 'r')
sys.stdout = open(FILENAME + ".out", 'w')

def solve(line):
    return ''.join( sorted(line.split()[1:], cmp = lambda a,b: cmp(a+b, b+a)) )

def get_line(): return raw_input()
def get_int(): return int(get_line())

if __name__ == '__main__':
    for case in range(get_int()):
        print(solve(get_line()))

8studious_student3.py

#! /usr/bin/env python3

FILENAME = "studious_student"
import sys
sys.stdin = open(FILENAME + ".in", 'r')
sys.stdout = open(FILENAME + ".out", 'w')

from functools import cmp_to_key

def solve(line):
    return ''.join( sorted(line.split()[1:], key=cmp_to_key(cmp_join_str)) )

def cmp(a,b): return (a > b) - (a < b)
def cmp_join_str(a,b): return cmp(a+b, b+a)

def get_line(): return input()
def get_int(): return int(get_line())

if __name__ == '__main__':
    for case in range(get_int()):
        print(solve(get_line()))

9studious_student_small.py

#! /usr/bin/env python2

for _ in range(int(raw_input())):
	print(''.join( sorted(raw_input().split()[1:], cmp = lambda a,b: cmp(a+b, b+a))))