Factorial in Programs

发表于 2017-03-20   |   分类于 algorithm

Factorial in Lua

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function factorial(n)
    if (n == 0) then
        return 1
    else
        return n * factorial(n - 1)
    end
end
for n = 0, 16 do
    io.write(n, "! = ", factorial(n), "\n")
end

output:

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0! = 1
1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720
7! = 5040
8! = 40320
9! = 362880
10! = 3628800
11! = 39916800
12! = 479001600
13! = 6227020800
14! = 87178291200
15! = 1307674368000
16! = 20922789888000
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-- function closures are powerful
-- traditional fixed-point operator from functional programming
Y = function (g)
      local a = function (f) return f(f) end
      return a(function (f)
                 return g(function (x)
                             local c=f(f)
                             return c(x)
                           end)
               end)
end
-- factorial without recursion
F = function (f)
      return function (n)
               if n == 0 then return 1
               else return n*f(n-1) end
             end
    end
factorial = Y(F)   -- factorial is the fixed point of F
-- now test it
function test(x)
	io.write(x,"! = ",factorial(x),"\n")
end
for n=0,16 do
	test(n)
end

Factorial in Bash

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f=1
for (( n=1; $n<=17; $((n++)) ));
do
  echo "$((n-1))! = $f"
  f=$((f*n))
done
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factorial ()
{
    local num=$1;
    if [ $num = 0 ]; then
        echo 1
        return ;
    fi;
    echo $(( $num * $(factorial $(( $num - 1 )) ) ))
}
for ((n = 0; n <= 16; n++))
do
    echo "$n! = " $(factorial $(($n)))
done

Factorial in Python

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def factorial(n):
    if n == 0:
        return 1
    f = 1
    for i in range(1, n + 1):
        f *= i
    return f
for n in range(16 + 1):
    print "%d! = %d" % (n, factorial(n))

Factorial in Dart

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main() {
  int fact = 1;
  for (int i = 0; i <= 16; ++i, fact *= i) {
    print('$i! = $fact');
  }
}

Factorial in Java

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public class Factorial {
    static long factorial(int n)
    {
        return ( n==0 ? 1 : n*factorial(n-1) );
    }
    public static void main(String[] args)
    {
        for (int n=0; n<=16; n++)
            System.out.println(n+"! = "+factorial(n));
    }
}

Factorial in PHP

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<?php
function factorial($n)
{
    if ($n == 0) {
        return 1;
    }
    return $n * factorial($n - 1);
}
for ($n = 0; $n <= 16; $n++) {
    echo $n . "! = " . factorial($n) . "\n";
}
?>

Factorial in Objective-C

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#include <stdio.h>
unsigned long long factorial(unsigned long long n)
{
    if (n == 0) {
        return 1;
    } else {
        return n * factorial (n - 1);
    }
}
int main(void)
{
    int n;
    for (n = 0; n <= 16; n++) {
        printf("%i! = %lld\n", n, factorial(n));
    }
    return 0;
}

Factorial in C

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#include <stdio.h>
int main()
{
    int n, i;
    unsigned long long factorial = 1;
    printf("Enter an integer: ");
    scanf("%d",&n);
    // show error if the user enters a negative integer
    if (n < 0)
        printf("Error! Factorial of a negative number doesn't exist.");
    else
    {
        for(i=1; i<=n; ++i)
        {
            factorial *= i;              // factorial = factorial*i;
        }
        printf("Factorial of %d = %llu", n, factorial);
    }
    return 0;
}
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#include <stdio.h>
int main() {
   int loop;
   int factorial=1;
   int number = 5;
   for(loop = 1; loop<=number; loop++) {
      factorial = factorial * loop;
   }
   printf("Factorial of %d = %d \n", number, factorial);
   return 0;
}
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/*  Example Program For Find Factorial Number In C Programming Language
    little drops @ thiyagaraaj.com
    Coded By:THIYAGARAAJ MP             */
// Header Files
#include<stdio.h>
#include<conio.h>
// define Function and Its Argument Type
long factorial(long);
//Main Function
int main()
{
	// Variable Declaration for Factorial Function Input
	long f;
	printf("Enter the Number for Factorial Calculation :?);
	scanf("%ld",&f);
	//factorial calculation
	printf("The Factorial of %ld is %ld",f,factorial(f));
	// Wait For Output Screen
	getch();
	//Main Function return Statement
	return 0;
}
// factorial Function
long factorial(long n)
{
	int counter;
	long fact = 1;
	//for Loop for Factorial Calculation Block
	for (counter = 1; counter <= n; counter++)
	{
		fact = fact * counter;
	}
	return fact;
}

reference

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