Stuck on a simple problem: Find the sum of all the multiples of 3 or 5 below 1000.

Question

Hi need some help with the summing of this simple problem. Seems that it doesn't save on the arrays.
Here is the code:

using System;


namespace test
{
    class Program
    {
        static void Main()
        {
            Program p = new Program();
            p.sum(1000);


            Console.ReadLine();
        }


        public void sum (int tal)
        {
            for (int i = 1; i < tal; i++)
            {
                int[] array= new int[1000];
                if (i % 3 == 0 || i % 5 == 0)
                {
                    array[i] += i;
                    Console.WriteLine(array[i]);
                }
            }
        }
    }
}

Can someone give me the guidance to complete this one!?

Best regards,

Answer 1

Hi
   Declare array outside the for loop and get another variable total for sum...
You can display each number which is meet your condition i,e multiple of 3 or 5 and Lastly display Sum of these numbers. Use this code:-
using System;


namespace test
{
class Program
{
static void Main()
{
Program p = new Program();
p.sum(1000);


Console.ReadLine();
}


public void sum (int tal)
{
long total = 0;
int[] array= new int[1000];  //It does save in Array..(Here your problem get solved)
for (int i = 1; i < tal; i++)
{
if (i % 3 == 0 || i % 5 == 0)
{
array[i] += i;
 total = total + i;
Console.WriteLine(array[i]);
}
}
Console.WriteLine("Sum of multiple 3 or 5 below 1000= "+total);
}
}
}

Answer 2

Hi
   If your query resolved then mark as Correct Answer.

Answer 3

Thank you so much! :) I used this tips since I wanted to use Array.

Answer 4

Thank you so much! :) Good tips!

Answer 5

Hi.

Looking at your code I'm not sure of what you want to do... 

If you want to get the total sum, you should maybe do something like this:

namespace test
{
  class Program
  {
        static void Main(string[] args)
        {
                long totalSum = Sum(1000);
                Console.WriteLine(string.Format("Total sum: {0}", totalSum));
                Console.ReadLine();
        }

        public static long Sum(int tal)
        {
                long total = 0;
                for (int i = 1; i < tal; i++)
                {
                        if (i % 3 == 0 || i % 5 == 0)
                        {
                                total += i;
                        }
                }

                return total;
        }
   }

}