Freestyle Sparring

def sayHello(say):
    say.append("bulbul")
    return say

function greetLanguage(a = "Hello", b = "Javascript") { return `${a}, ${b}!`; }

using System;
using System.Linq;

public class Kata
{
      public static int DuplicateCount(string str)
      {
            return str
                .ToLower()
                .GroupBy(c => c)
                .Aggregate(0, (current, next) => current + (next.Count() > 1 ? 1 : 0));
      }

}

#include<stdio.h>

int hello(char* name) {
  printf("Hello, %s!\n", name);
  return 0;
}

const thirdGreatest = a => [...a].sort((a,b) => b - a)[2];

function countCirculars(n) {
  let count = 0;

  for (let i=3;i<=n; i+=2) {
    if (isPrime(i) && isCirclePrime(i))
      count++;
  }

  return count+1;
}

function isPrime(n) {
  if (n <= 1)
    return false
  else if (n <= 3)
    return true
  else if ((n % 2) === 0 || n % 3 === 0)
    return false

  let i = 5;

  while (i*i <= n) {
    if (n % i === 0 || n % (i + 2) === 0)
      return false
    i = i + 6
  }
  return true
}

function isCirclePrime(n) {
  let strN = n.toString();
  for (let i = 1; i<strN.length; i++) {
    strN = shiftString(strN);
    if (!isPrime(parseInt(strN)))
      return false
  }
  return true;
}

function shiftString(str) {
  return str.substring(1) + str.substring(0,1);
}

package com.mystuff.juststuff;

import java.text.*;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TreeSet;

public class Palindrome {
	SimpleDateFormat sdf;
	
	public Palindrome() {
		this.sdf = new SimpleDateFormat("MMddyyyy");
		sdf.setLenient(false);
	}

	public TreeSet<Date> countDatePalindromes(Date startDate, Date endDate) {
		TreeSet<Date> palSet = new TreeSet<Date>();
		GregorianCalendar startCal = new GregorianCalendar();
		GregorianCalendar endCal = new GregorianCalendar();


    /*
      end date is chronologically before start date. flip them.
      NOTE: lines 23-30 should be a pre-condition to the countDatePalindromes method,
      so they should be deleted.
    */
		if (startDate.getTime() > endDate.getTime()) {
			startCal.setTime(endDate);
			endCal.setTime(startDate);
		}else {
			startCal.setTime(startDate);
			endCal.setTime(endDate);
		}

		String regularDate = null;
		String palDate = null;
		while ( (startCal.before(endCal)) || (startCal.equals(endCal)) ) {
			regularDate = sdf.format(startCal.getTime());
			palDate = palindromify(startCal.getTime());			
      
      // a date palindrome was found
			if (regularDate.equals(palDate))
				palSet.add(startCal.getTime());
        
			startCal.add(Calendar.DAY_OF_MONTH, 1);
		}	
		return palSet;
	}
	
	private String palindromify(final Date arg) {
		StringBuffer palBuff = new StringBuffer(8);
    palBuff = sdf.format(arg, palBuff, new FieldPosition(0));
		return palBuff.reverse().toString();
	}

}

using System.Linq;   
public class Kata { public static string[] LiningUpHisStudents(string s) => s.Split(' ').OrderByDescending(x => x.Length).ThenByDescending(x => x).ToArray(); }