When the input is 25
the expected output is 15511210043330985984000000
and not 1.551121e+25
. The parsing though is solved by Decimal.Parse(factorial.ToString(), System.Globalization.NumberStyles.Float)
.
I cannot get to calcuate for bigger numbers like 95.
using System;
namespace bigNumber
{
class Program
{
static void Main(string[] args)
{
int number = Convert.ToInt32(Console.ReadLine());
long factorial = 1;
for (int i = number; i > 0; i--)
{
factorial = factorial * i;
}
Console.WriteLine(factorial);
}
}
}
As stated above, the BigInteger is a good candidate, as it can hold an arbitrarily large signed integer:
namespace ConsoleApplication4
{
using System;
using System.Numerics;
class Program
{
static void Main(string[] args)
{
Console.WriteLine(Factorial(0));
Console.WriteLine(Factorial(25));
Console.WriteLine(Factorial(95));
}
private static BigInteger Factorial(int number)
{
BigInteger factorial = 1;
for (var i = number; i > 0; i--)
{
factorial *= i;
}
return factorial;
}
}
}
1
15511210043330985984000000
10329978488239059262599702099394727095397746340117372869212250571234293987594703124871765375385424468563282236864226607350415360000000000000000000000
Press any key to continue . . .