factorial

Currently I have this set of code and its meant to calculate factorials. int numberInt = int.Parse(factorialNumberTextBox.Text); for (int i = 1; i < numberInt; i++) { numberInt = numberInt * i; } factorialAnswerTextBox.Text = numberInt.ToString(); For some reason it doesn't work and i have no clue why. For example i will input 3 and get the answer as -458131456 which seems really strange. Any help appreciated. Thanks int numberInt = int.Parse(factorialNumberTextBox.Text); int result = numberInt; for (int i = 1; i < numberInt; i++) { result = result * i; } factorialAnswerTextBox.Text = result

i came across the following program for calculating large factorials(numbers as big as 100).. can anyone explain me the basic idea used in this algorithm?? I need to know just the mathematics implemented in calculating the factorial. #include <cmath> #include <iostream> #include <cstdlib> using namespace std; int main() { unsigned int d; unsigned char *a; unsigned int j, n, q, z, t; int i,arr[101],f; double p; cin>>n; p = 0.0; for(j = 2; j <= n; j++) p += log10(j); d = (int)p + 1; a = new unsigned char[d]; for (i = 1; i < d; i++) a[i] = 0; //initialize a[0] = 1; p = 0.0; for (j = 2; j <= n; j+

I tried to find the factorial of a large number e.g. 8785856 in a typical way using for-loop and double data type. But it is displaying infinity as the result, may be because it is exceeding its limit. So please guide me the way to find the factorial of a very large number. My code: class abc { public static void main (String[]args) { double fact=1; for(int i=1;i<=8785856;i++) { fact=fact*i; } System.out.println(fact); } } Output:- Infinity I am new to Java but have learned some concepts of IO-handling and all. public static void main(String[] args) { BigInteger fact = BigInteger.valueOf(1);

When doing this: int x = 100; int result = 1; for (int i = 1; i < (x + 1); i++) { result = (result * i); } System.out.println(result); This is clearly because the result is too big for an integer, but I am used to get big negative numbers for the overflow, and not 0. Thanks in advance! When I switch to this: int x = 100; int result = 1; for (int i = 1; i < (x + 1); i++) { result = (result * i); System.out.println(result); } I get this . Big negative numbers are values that overflowed into certain ranges; factorial(100) has more than 32 binary zeros on the end, so converting it to an integer

I understand this is a classic programming problem and therefore I want to be clear I'm not looking for code as a solution, but would appreciate a push in the right direction. I'm learning C++ and as part of the learning process I'm attempting some programming problems. I'm attempting to write a program which deals with numbers up to factorial of 1billion. Obviously these are going to be enormous numbers and way too big to be dealing with using normal arithmetic operations. Any indication as to what direction I should go in trying to solve this type of problem would be appreciated. I'd rather

I get the following results on my machine: Python 3.2.2 (default, Sep 4 2011, 09:51:08) [MSC v.1500 32 bit (Intel)] on win 32 Type "help", "copyright", "credits" or "license" for more information. >>> import timeit >>> timeit.timeit('factorial(10000)', 'from math import factorial', number=100) 1.9785256226699202 >>> Python 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)] on win 32 Type "help", "copyright", "credits" or "license" for more information. >>> import timeit >>> timeit.timeit('factorial(10000)', 'from math import factorial', number=100) 9.403801111593792 >>> I

I'm going crazy: Where is the Ruby function for factorial? No, I don't need tutorial implementations, I just want the function from the library. It's not in Math! I'm starting to doubt, is it a standard library function? There is no factorial function in the standard library. Like this is better (1..n).inject(:*) || 1 Pierre-Antoine LaFayette It's not in the standard library but you can extend the Integer class. class Integer def factorial_recursive self <= 1 ? 1 : self * (self - 1).factorial end def factorial_iterative f = 1; for i in 1..self; f *= i; end; f end alias :factorial :factorial

I am trying to write a Java program to calculate factorial of a large number. It seems BigInteger is not able to hold such a large number. The below is the (straightforward) code I wrote. public static BigInteger getFactorial(BigInteger num) { if (num.intValue() == 0) return BigInteger.valueOf(1); if (num.intValue() == 1) return BigInteger.valueOf(1); return num.multiply(getFactorial(num.subtract(BigInteger.valueOf(1)))); } The maximum number the above program handles in 5022, after that the program throws a StackOverflowError . Are there any other ways to handle it? The problem here looks