Problem in question FCTRL2

general
,
1

Hi Guys,

I recently encountered a problem in the beginner question FCTRL2.
This is my code:

#include <stdio.h>

int main()
{
  int t,i,j,n,fact=1,l;
  scanf("%d",&t);
  int a[t-1];
  
  for(i=1;i<=t;i++)
  {
    scanf("%d",&n);
    
    for(j=1;j<=n;j++)
    {
       fact=fact*j;
    }
    a[i-1]=fact;
    fact=1;
  }
  
  for(l=0;l<=(t-1);l++)
  {
    printf("%d\n",a[l]);
  }

  return 0;
}

This produced the desired output when I ran it in Dev C++. However, when I submit my question, they keep telling it is a wrong answer.
I would like to know whether my approach to the problem is wrong or not.

Thank you.

2

Try to think the range of output.(till 100! too large to use int or even long).
try this test case you will understand
2
99
100

3

Well it should give wrong answer indeed. You are using int data type which has a range of approximately 10^9 but the constraints of the problem are upto 100 .
100!=93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000
So obviously this integer won’t fit in int data type and for that matter it won’t even fit in long long int or unsigned long long int .
So you need to change your approach and once you are done with coding check the value of 100! once to get an idea whether your code is correct or not.

4

Hi guys!

Thanks for your feedback. I understood my problem. If it were Java or Python I could use the Big Integer class. I am not sure whether they work on C/C++. I guess the safest way were to treat my numbers as strings and carry on with my code, if I am correct.

5

By strings i mean using arrays. The word strings isn’t appropriate here.

6

@sarfu2k
yes in c/c++ you can go with arrays to solve this question.