Factorials of large numbers

Given an integer N, find its factorial.

Example 1:

Input: N = 5
Output: 120
Explanation : 5! = 1*2*3*4*5 = 120

Example 2:

Input: N = 10
Output: 3628800
Explanation :
10! = 1*2*3*4*5*6*7*8*9*10 = 3628800

Example 3:

Input: N = 30
Output:  .
Explanation :
30! =    

Note: Factorials of  can't be stored even in a  long long variable. Big integers must be used for such calculations. Languages like Java, Python, Ruby etc. can handle big integers, but we need to write additional code in C/C++ to handle huge values.

We recommend solving this challenge using BigIntegers.

c++ implementation:

int multiply(int x,int a[],int size)
{
    int carry=0;
    for(int i=0;i<size;i++)
    {
        int p=(a[i]*x)+carry;
        a[i]=p%10;
        carry=p/10;
        
    }
    
    while(carry)
    {
        a[size]=carry%10;
        carry=carry/10;
        size=size+1;
        
    }
    return size;
}
void extraLongFactorials(int n) 
{
    int a[10000];
    a[0]=1;
    int size=1;
    
    for(int i=2;i<=n;i++)
    {
        size=multiply(i,a,size);
    }
    
    for(int i=size-1;i>=0;i--)
    cout<<a[i];
}