wrong answer on spoj.pl???

[ThermoSight]

the following code appears to run OK on my machine (for the unconscionably few test points I tried) ....

        // ****************************************

        private long myVersionOfHisMain() {
            return factorial(Int32.Parse(textBox2.Text));
        }

        private long factorial(long d)  {

            long c = 0;
            long e = 1;
            long j = 1;
            while (c < d)
            {
                j = j * e;
                c++;
                e++;
            }
            return j;
        }
    // ********************************************************


   and called as follows ...

            textBox1.Text = myVersionOfHisMain().ToString();

It is not entirely clear to me what your intent was in "Main", and it's too late at night for me to check the code ... the Tonight Show is almost on. I note what appears at first glance to be a "console.ReadLine" in the middle of a WHILE loop, that must be fun, and an IF that seems questionable to this admittedly novice programmer ...
"if (n < 100) ;"

But your "factorial" function came up running (at least insofar as my HP calculator was able to confirm).


I had two versions of factorial ...

        // ***************************************
        private long calculate(int n) {

            if (n >= 0)
                if (n < 2)
                    return 1;
                else
                    return n * calculate(n - 1);
            else
                return -1;
        }
        // **************************************


        // **************************************
        private long AltCalculate(int n) {
            int cnt = 2;
            long product = 1;

            if (n >= 0)
                while (cnt <= n) {
                    product *= cnt++;
                }
            else
                product = -1;

            return product;
        }
        // ***************************************


called as follows ...
            textBox1.Text = calculate(Int32.Parse(textBox2.Text)).ToString();