How to print factorial series in C#?

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How to print following factorial series in C#...
1!+2!+3!+4!.....
and
1/1!+1/2!+1/3!+1/4!....

Plz help out..

Posted 8-Dec-14 18:32pm

Member 11242836

Updated 23-Jul-20 3:59am

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/\jmot 9-Dec-14 1:03am

Not clear?
be more specific..

Member 11242836 9-Dec-14 1:19am

I wanted to get sum of those factorials.
ex. 1!+2! = 3.
so till the value given by user..I want the sum till that..

Shanish K 9-Dec-14 1:04am

Do you have to print just the series, or the result as well? Can you please elaborate how the result should be?

Member 11242836 9-Dec-14 1:17am

I wanted the result as well...the result should br the sum of those factorials
Thnk u

_Maxxx_ 9-Dec-14 1:08am

It is expected that you make some attempt before asking people to help you do your homework

syed shanu 9-Dec-14 1:10am

Google can give you better answer.Lots of samples available their

Member 11242836 9-Dec-14 1:14am

I searched google.. n made attempts...
I am not asking u all to do my homework... I Culdnt figure it out so askd...
@syed shanu and @_Maxxx_

syed shanu 9-Dec-14 1:38am

Check my solution hope you get what you want now.

Ankur^\m/ 9-Dec-14 1:17am

Homework?!
Write a method that calculates factorial of a given number. That's the most important thing. Next step is to find the value of a given expression. If it's just calculating the factorial 4 times, call the method 4 times. If it's some kind of series, write another method where you will pass 'n' where n is the number till which the factorial will be calculated. In this method you will call the first method you wrote n times.
You gotta BEGIN first.

Member 11242836 9-Dec-14 1:23am

ohk...thanks.. i got u nw...
I already did how to get factorial of a given no. bt i was not getting this series...
Thnk u...

Ankur^\m/ 9-Dec-14 1:30am

Okay I will move it to answer then. It will help others searching for similar questions.
You can also ask any specific questions there after you have tried.

Member 11242836 9-Dec-14 1:31am

ya...Thnks.. :)

Raul Iloc 9-Dec-14 1:36am

I do not agree with you, that you should invoke the factorial method "n" times for a series is an optimal solution. Look on my solution below and you could see the optimal solution that is doing the computation of all series in one loop.

Raul Iloc 9-Dec-14 1:28am

I just updated my solution to compute and "print" also the values of both expressions.

Raul Iloc 9-Dec-14 1:42am

1.Did you see the update in my solution?
2.Now I am also compute each series in one single loop, this is much optimal solution that the solution accepted by you, because each factorial depend on the previous value ("n! = n * (n-1)!"), so invoking the procedure "n" times is not an optimal solution!

Ankur^\m/ 9-Dec-14 1:59am

No it is not. For every factorial related series you are gonna write a new code? You have done everything inside one method. I suggested the same thing to be segregated. The time taken for calculation in both the technique will be same.

Ankur^\m/ 9-Dec-14 2:10am

Okay in this specific scenario, the code can be further optimized by multiplying the current number to the last factorial found. But I think the time taken for calculation in both the methods will be same unless this is done for very high value of n. I will do a test and post the results.

Andreas Gieriet 9-Dec-14 2:23am

I wonder that no one (or did I miss it) mentioned that the first series easily and quickly reaches the limit of your variables integer value range. Depending on your chosen variable type, you reach the limit with n = 13 or n = 20.
The second series results in e - the more terms you add, the closer it gets to the real value of e = 2.718281828...
Cheers
Andi

3 solutions

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Ankur^\m/ · Accepted Answer · 2014-12-08T19:31:00

Solution 3

Write a method that calculates factorial of a given number. That's the most important thing. Next step is to find the value of a given expression. If it's just calculating the factorial 4 times, call the method 4 times. If it's some kind of series, write another method where you will pass 'n' where n is the number till which the factorial will be calculated. In this method you will call the first method you wrote n times using a loop (while / for).
You gotta BEGIN first.

Posted 8-Dec-14 19:31pm

Ankur^\m/

Comments

Raul Iloc 9-Dec-14 1:36am

I do not agree with you, that you should invoke the factorial method "n" times for a series is an optimal solution. Look on my solution above and you could see the optimal solution that is doing the computation of all series in one loop.

Ankur^\m/ 9-Dec-14 1:54am

Your solution isn't "Reusable". Reusability principle says that you should create methods for reusable codes.
Code to find a Factorial will be same. So you can create a method for it and you don't need to write it every time a new type of expression is given.

Raul Iloc 9-Dec-14 2:15am

Is not like this! My entire code, for each series, could be put into a single method that should have one param "n".

Ankur^\m/ 9-Dec-14 2:22am

And that is what I suggested. First thing I said was to create a method to calculate factorial of a number. And then depending on the expression, next approach should be decided.

Raul Iloc 9-Dec-14 2:42am

No, my suggestion is to use only one method for computing the entire series and not to use "n" time a method for each factorial!

Ankur^\m/ 9-Dec-14 7:23am

I did some tests and as I said, your computation method is faster. But that is noticeable for very high values of n.
Anyways my answer was a suggestion on how to go about the solution. I never wrote any code and left that for the user to do. Once he was able to write a solution, optimization would have been the next step. I am sure there are other faster methods of calculations than what you have suggested. Level of optimization depends on the type of application one is building.

You were too fast to vote the answer and I think the answer doesn't deserve a down-vote (reasons mentioned above).

Raul Iloc · Accepted Answer · 2014-12-08T19:17:00

1.For first expression you should do like in the next example:

C#

int n = 10;
            StringBuilder builder = new StringBuilder();
            double resultValue = 0;
            double temp = 1;
            for (int i = 0; i < n; i++)
            {
                if (i > 0)
                    builder.Append(" + ");
                builder.Append(string.Format("{0}!", i + 1));
                temp *= (i + 1);
                resultValue += temp;
            }
            //
            builder.Append(string.Format(" = {0}", resultValue));
            _textBox.Text = builder.ToString();

2.For 2nd expression a similar code like below:

C#

int n = 10;
            StringBuilder builder = new StringBuilder();
            double resultValue = 0;
            double temp = 1;
            for (int i = 0; i < n; i++)
            {
                if (i > 0)
                    builder.Append(" + ");
                builder.Append(string.Format("1/{0}!", i + 1));
                temp *= (i + 1);
                resultValue += 1/temp;
            }
            //
            builder.Append(string.Format(" = {0}", Math.Round(resultValue, 2)));
            _textBox.Text = builder.ToString();

syed shanu · Accepted Answer · 2014-12-08T19:37:00

Solution 4

Check this code hope this will help you.

C#

//The fucntion can be called in page load or in button click or as you like.
 protected void Page_Load(object sender, EventArgs e)
    {
       // Call your fucntion here and pass your input to this method
        String Factorials = YourFactorial(3);
    }

 public String YourFactorial(int n)
    {

        if (n <= 1)
        {
            return " 1! :" + " The result is : 1" ;
        }

        int result = 1;

        String results = "";
        results = "1! + ";
        for (int i = 2; i <= n; i++)
        {
            results =results + i.ToString()+" ! + ";
            result = result * i;

        }

        return results + " The result is :" + result;

    }

Posted 8-Dec-14 19:37pm

syed shanu

Comments

Member 11242836 9-Dec-14 1:43am

Thnk u...

Ankur^\m/ 9-Dec-14 1:56am

I already described this technique in my answer. Let him try. You writing code for him isn't going to help him.

syed shanu 9-Dec-14 1:59am

Hi,
Well you can see my comment for him.as he again requested for the solution i did for him this is very simple solution for us but for starter it seems hard

Ankur^\m/ 9-Dec-14 2:01am

And you writing code for him isn't going to make him learn. Let him try and show what he did and where he got stuck. Then you could have helped him with that.

syed shanu 9-Dec-14 2:02am

Cool

Ankur^\m/ 9-Dec-14 2:31am

I just saw your answer again. You are also returning string. That is not asked.

syed shanu 9-Dec-14 2:32am

OOPs it has both integer and string the user can use what he want.

How to print factorial series in C#?

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How to print factorial series in C#?

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