Форум StopLinux

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace ConsoleApplication1
{
    class Program
    {
        static int Brute(int[] numbers )
        {
            int delta = numbers[numbers.Length - 1];
            for (int value = delta; ; value += delta)
            {
                bool result = true;
                foreach (var number in numbers)
                {
                    if (value % number != 0)
                    {
                        result = false;
                        break;
                    }
                }
                if(result) return value;
            }
        }

        #region GCD of two integers
       
        public static int GCD(int Value1, int Value2)
        {
            int a;            // local var1
            int b;            // local var2
            int _gcd = 1;     // Greates Common Divisor

            try
            {
                // throw exception if any value=0
                if (Value1 == 0 || Value2 == 0)
                {
                    throw new ArgumentOutOfRangeException();
                }

                // assign absolute values to local vars
                a = Math.Abs(Value1);
                b = Math.Abs(Value2);

                // if numbers are equal return the first
                if (a == b) { return a; }
                // if var "b" is GCD return "b"
                else if (a > b && a % b == 0) { return b; }
                // if var "a" is GCD return "a"
                else if (b > a && b % a == 0) { return a; }

                // Euclid algorithm to find GCD (a,b):
                // estimated maximum iterations: 
                // 5* (number of dec digits in smallest number)
                while (b != 0)
                {
                    _gcd = b;
                    b = a % b;
                    a = _gcd;
                }
                return _gcd;
            }
            catch { throw; }
        }
        #endregion

        #region LCM of two integers
       
        public static int LCM(int Value1, int Value2)
        {
            try
            {
                int a = Math.Abs(Value1);
                int b = Math.Abs(Value2);

                // perform division first to avoid potential overflow
                a = checked((int)(a / GCD(a, b)));
                return checked((int)(a * b));
            }
            catch { throw; }
        }
        #endregion

        static int Hz(int[] numbers)
        {   
            int value = 1;
            if (numbers.Length == 1) return numbers[0];
            List<int> lcms=new List<int>();
            for (int i = 0; i < numbers.Length-1; i++)
            {
                lcms.Add((int) LCM(numbers[i], numbers[i + 1]));
            }
            return Hz(lcms.ToArray());
        }

        static void Main(string[] args)
        {
            var numbers = Enumerable.Range(1, 20).ToList();
            
            //start timer
            Stopwatch timer = new Stopwatch();
            timer.Start();

            //array filtration
            for(int right = 0; right<numbers.Count; right++)
            {
                int rightIndex = numbers.Count - 1 - right;

                for (int left = 0; left < rightIndex; left++)
                {
                    if (numbers[rightIndex] % numbers[left] == 0)
                    {
                        numbers.RemoveAt(left);
                        left--;
                        rightIndex--;
                    }
                }
            }

            int value = Hz(numbers.ToArray());
           
            //stop timer
            timer.Stop();

            //see what we've got after filtration and result
            numbers.ForEach(Console.WriteLine);
            Console.WriteLine("End in {0} ms. Value is {1}", timer.ElapsedMilliseconds, value);
        }
    }
}

#!/usr/bin/perl -w
for ($i=999; $i>900; $i--)
{
    # Формируем палиндром
    @symbols = split(//,$i);
    $palindrome = $i.$symbols[2].$symbols[1].$symbols[0];
    
    # Ищем наибольший делитель
    for ($j=999; $j>900; $j--)
    {
        if( ($palindrome % $j == 0)&&($palindrome / $j < 1000) )
        {
            print "$palindrome = $j * ", $palindrome/$j," \n";
            exit();
        }
    }
}