unsigned long nfact (unsigned long N) return N==1 ? 1 : nfact (N-1);
This algorithm, like all limited precision algorithms, suffers from overflow after only a few recursions. If, for instance, an unsigned long was 32 bits long, the largest factorial that could be computed would by 12! or 479,001,600. 13! or 6,227,020,800 would overflow the maximum 32 bit unsigned result of 4,294,967,295.
Attached is an arbitrary length algorithm, based on linked lists of decimals, that will compute factorials to nearly any length. It also calculates them using less sophisticated means, with varying precisions, so you can see where the overflow occurs. In order to compute very very large factorials, you will need to tell your linker to increase the run-time stack size.
// Factorial.cpp : Defines the entry point for the console application.
//
#include <stdlib.h>
#include <stdio.h>
/* Microsoft 32-bit iterative */
unsigned long NFactLongIterative (unsigned long N) {
unsigned long result = N;
if (N < 2) return 1;
if (N 2) {
decimal_initialize (d, 2);
return;
}
while (N > 2) {
decimal_multiply (d, N);
N--;
}
return;
}
/* Example main line */
/* Generates all variations to show differences in results */
int main (int argc, char *argv[]) {
int N;
decimal Decimal = {2, NULL};
if (argc < 2) {
printf ("Enter N (or use command line) : ");
scanf_s ("%d", &N);
} else {
N = atoi (argv[1]);
}
printf ("Long: %u! = %u\n", N, NFactLongIterative (N));
printf ("LongLong: %u! = %I64u\n", N, NFactLongLongIterative (N));
printf ("Recursive: %u! = %I64u\n", N, NFactLongLongRecursive (N));
printf ("Double: %u! = %.0f\n", N, NFactDouble (N));
/* note: arbitrary is exact - if the others don't match, arithmetic overflow occurred */
printf ("Arbitrary: %u! = ", N);
decimal_NFactIterative (&Decimal, N);
decimal_print_digits (&Decimal, true);
return 0;
}
import java.math.BigInteger; public class Factorial { public static void main(String[] args) { BigInteger n = BigInteger.ONE; for (int i=1; i<=20; i++) { n = n.multiply(BigInteger.valueOf(i)); System.out.println(i + "! = " + n); }
A flowchart for factorial of number can be made using different software's. Microsoft Word is the most popular software for beginners to make simple flowcharts.In order to draw the flowchart write the number at the top of the paper and then draw two lines under it going slightly to the sides. Decide what two numbers can be multiplied to equal that number. Keep going until you can no longer get to smaller numbers.
factorial using recursion style in c++ is unsigned int fact(unsigned int a) { if (a<=1) return 1; else { f*=fact(a-1); return a; } } when using looping structure factorial is unsigned int fact (unsigned int n) { unsigned int i,f=1; for(i=1;i<=n;i++) f*=i ; return f; }
/*71.PROGRAM TO FIND FACTORIAL OF A NUMBER USING RECURSION*/ #include<stdio.h> #include<conio.h> int fact(int); void main() { int n,f; clrscr(); printf("Enter number whose factorial is to be calculated: "); scanf("%d",&n); if(n>0) { f=fact(n); printf("factorial of %d is %d",n,f); } else printf("Factorial of numbers less than 1 does not exist"); getch(); } int fact(int n) { int facto=1; if(n>1) facto=n*fact(n-1); else return 1; return(facto); }
#include <iostream> using namespace std; int main() { int i, number=0, factorial=1; // User input must be an integer number between 1 and 10 while(number<1 number>10) { cout << "Enter integer number (1-10) = "; cin >> number; } // Calculate the factorial with a FOR loop for(i=1; i<=number; i++) { factorial = factorial*i; } // Output result cout << "Factorial = " << factorial << endl;
no answer....pls post
import java.math.BigInteger; public class Factorial { public static void main(String[] args) { BigInteger n = BigInteger.ONE; for (int i=1; i<=20; i++) { n = n.multiply(BigInteger.valueOf(i)); System.out.println(i + "! = " + n); }
A flowchart for factorial of number can be made using different software's. Microsoft Word is the most popular software for beginners to make simple flowcharts.In order to draw the flowchart write the number at the top of the paper and then draw two lines under it going slightly to the sides. Decide what two numbers can be multiplied to equal that number. Keep going until you can no longer get to smaller numbers.
A recursive method (or function) is one that calls itself. Here is a popular example: The factorial function n! (read the exclamation mark as: factorial of n, or n factorial), for a positive integer, is the product of all numbers up to that number. For example, 4! = 1 x 2 x 3 x 4. In math, the factorial is sometimes defined as: 0! = 1 n! = n x (n-1)! (for n > 0) You can write a function or method, using this definition. Here is the pseudocode: function factorial(n) if (n = 0) return 1 else return n * factorial(n - 1) Note that this is not very efficient, but there are many problems that are extremely complicated without recursion, but which can be solved elegantly with recursion (for example, doing something with all files in a folder, including all subfolders).
recursion is always slower than iteration
factorial using recursion style in c++ is unsigned int fact(unsigned int a) { if (a<=1) return 1; else { f*=fact(a-1); return a; } } when using looping structure factorial is unsigned int fact (unsigned int n) { unsigned int i,f=1; for(i=1;i<=n;i++) f*=i ; return f; }
/*program to find the factorial of a given number*/ #include<stdio.h> #include<conio.h> int fact(int); void main() { int n,c; printf("\n enter the number for which you want to find the factorial"); scanf("%d",&n); c=fact(n); printf("\n the factorial of the number %d is %d",n,fact); getch(); } int fact(int n) { int k; if(n==0) return(1); else k=n*fact(n-1); return(k); }
/*71.PROGRAM TO FIND FACTORIAL OF A NUMBER USING RECURSION*/ #include<stdio.h> #include<conio.h> int fact(int); void main() { int n,f; clrscr(); printf("Enter number whose factorial is to be calculated: "); scanf("%d",&n); if(n>0) { f=fact(n); printf("factorial of %d is %d",n,f); } else printf("Factorial of numbers less than 1 does not exist"); getch(); } int fact(int n) { int facto=1; if(n>1) facto=n*fact(n-1); else return 1; return(facto); }
Let's take the example of finding the factorial of a number (of a positive integer). The factorial of N is N * (N-1) * (N-2) * (N-3) ... * 3 * 2 *1 It is the product of all integers between that number (including that number) and 1. For example, factorial 2 = 2*1 = 2 factorial 3 = 3*2*1 = 6 factorial 4 = 4*3*2*1= 24 Now you define a recursive function Fac (N) as Fac (N) = Fac (N-1) * N, with Fac(1) predefined as 1. Thus, Fac(N-1) = Fac(N-2) * (N-1) and Fac(N-2) = Fac(N-3) * (N-2) and thus recursion takes over until such time fac(1) needs to be evaluated. We know the value of Fac(1) which is set as 1. Thus we can evaluate Factorial(N) using recursion.
factorial n is given by formula n! = n.(n-1)....1 int i; long x; x =1; for (i=n;i>1;i--) x = x*i ; will calculate factorial. I have put x as long to avoid integer overflow. checks for n is positive etc. to be added.
#include <iostream> using namespace std; int main() { int i, number=0, factorial=1; // User input must be an integer number between 1 and 10 while(number<1 number>10) { cout << "Enter integer number (1-10) = "; cin >> number; } // Calculate the factorial with a FOR loop for(i=1; i<=number; i++) { factorial = factorial*i; } // Output result cout << "Factorial = " << factorial << endl;
The factorial f(n) = n * (n-1) * (n-2) * .. 1. For example factorial 5 (written as 5!) = 5 x 4 x 3 x 2 x 1 = 120. The function below returns the factorial of the parameter n. int factorial( int n) { if (n==1) return 1 else return n* factorial( n-1) ; }