in last case it shows run time error
#include
using namespace std;
#define MAX 500
int multiply(int x, int res[], int res_size);
void factorial(int n)
{
int res[MAX];
res[0] = 1;
int res_size = 1;
for (int x=2; x<=n; x++)
res_size = multiply(x, res, res_size);
for (int i=res_size-1; i>=0; i--)
cout << res[i];
}
int multiply(int x, int res[], int res_size)
{
int carry = 0;
for (int i=0; i<res_size; i++)
{
int prod = res[i] * x + carry;
res[i] = prod % 10;
carry = prod/10;
}
while (carry)
{
res[res_size] = carry%10;
carry = carry/10;
res_size++;
}
return res_size;
}
int main()
{
int n;
cin>>n;
factorial(n);
return 0;
}