factorial

问题 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

问题 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. 回答1: Big negative numbers are values that overflowed into

问题 I have written this function to return the factorial of a given number func factorial(_ n: Int) -> Int { if n == 0 { return 1 } else { return n * factorial(n - 1) } } print( factorial(20) ) // 2432902008176640000 Works as it should, as long the given number does not exceed 20, because then the result becomes too high! How can I circumvent this limit and thus calculate the factorial of higher numbers? I have searched around and found some bignum libraries for Swift. I'm doing this to learn and

问题 I found this page describing a number of algorithms for computing the factorial. Unfortunately, the explanations are terse and I don't feel like sifting through line after line of source code to understand the basic principles behind the algorithms. Can anybody point me to more detailed descriptions of these (or other fast) algorithms for computing the factorial? Edit: This page describes the method of prime factorization, the technique common to all of the best-performing factorial

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 2 years ago . How can I write a program to find the factorial of any natural number? 回答1: This will work for the factorial (although a very small subset) of positive integers: unsigned long factorial(unsigned long f) { if ( f == 0 ) return 1; return(f * factorial(f - 1)); } printf("%i",

问题 I was recently asked, in an interview, to describe a method to calculate the factorial of any arbitrarily large number; a method in which we obtain all the digits of the answer. I searched various places and asked in a few forums. But I would like to know if there is any way to accomplish this without using libraries like GMP. Thank you. 回答1: GNU Multiprecision library is a good one! But since you say using of external libraries are not allowed, only way I believe its possible is by taking an

问题 My factorial method is working correctly although I would like to change the output from just outputting the number and the factorial result. For example I would like if the user enters 6 for the output to say 6 * 5 * 4 * 3 * 2 * 1 = 720, instead of factorial of 6 is: 720. int count, number;//declared count as loop and number as user input int fact = 1;//declared as 1 Scanner reader = new Scanner(System.in); // Reading from System.in System.out.println("Please enter a number above 0:");

问题 The code #!/usr/bin/awk # Sed and AWK by O'Reilly (p.179) # Example of what should happen: factorial 5 gives # factorial # Enter number: 3 # The factorial of 3 is 6 BEGIN { printf("Enter number: ") } $1 ~ /^[0-9]+$/ { # assign value of $1 to number & fact number = $1 if (number == 0) fact = 1 else fact = number for (x = 1; x < number; x++) fact *=x printf("The factorial of %d is %g\n", number, fact) exit } # if not a number, prompt again. { printf("\nInvalid entry. Enter a number: ") } I run

问题 Okay, so I have been searching the internet and have found many things related to this question. However, I am not able to put the pieces together in order to figure this out. The requirements are to calculate a large factorial (e.g. 999!) USING LINKED LISTS and NODES. There are many people online that have shown a basic way of calculating a factorial and I understand how to do the factorial part, but the part I am having trouble with is filling each node with an Int between 0-999 (a three

问题 My code import sys number=int(sys.argv[1]) if number == 0 fact=1 else fact=number for (x=1; x<number; x++) fact*=x; // mistake probably here print fact I get the error File "factorial.py", line 5 if number == 0 ^ SyntaxError: invalid syntax How can you make a factorial function in Python? 回答1: Here's your code, fixed up and working: import sys number = int(sys.argv[1]) fact = 1 for x in range(1, number+1): fact *= x print fact (Factorial zero is one, for anyone who didn't know - I had to look