Factorial in c program using for loop?

Answer 1

#include<stdio.h>

#include<conio.h>

void main()

{

int i,n,fact=1;

clrscr();

printf("enter the number");

scanf("%d",&n);

for(i=1;i<=n;i++)

printf("%d",n);

fact=fact*i;

{

printf("the factorial is=%d",fact);

}

getch();

}

By:-Abhishek Goyal(goyal.abhi40@Yahoo.com)

Answer 2

The problem with factorials is that small numbers have huge factorials. Even a 64-bit unsigned int is only capable of storing 20 factorial (denoted 20!). Therefore any factorial function that returns a 64-bit unsigned int must assert for values greater than 20.

The for loop version would be:

UINT64 factorial (UINT64 num)

{

assert (num<21);

UINT64 result = 1;

for(UINT64 n=2; n<=num; result *= n++);

return result;

}

However, a while loop is more efficient as a counter is not required:

UINT64 factorial (UINT64 num)

{

assert (num<21);

UINT64 result = 1;

while (1 < num) result *= num--;

return result;

}

To accommodate factorials greater than 20, you have to create a user-defined class to accommodate the result as there are no built-in types available.

Answer 3

#include int main() { int fact,Factorial; printf("Please Enter Factorial Number\n"); scanf("%d",&fact); Factorial=func_fact(fact); printf("factorial is %d\n",Factorial); } int func_fact(int number) { int i; int factorial=1; for(i=number;i>=1;i--) { factorial=factorial*i; } return factorial; }