The factorial of a larger integer n, because n is larger than the normal type of the factorial of the expression range, using an array of operations (Java implementation)

package net.yk.mlgorithm;/** *  factorial  *  @author  administrator * * for larger numbers   @param  <T> */public class ArraysMul<T> {public static  Void main (String[] args)  {int[] array = factorial (+);p rintnum (array);} /** *  calculates two two-group multiply  *  @param  a  *  @param  b *  @return   The number represented by the array  */public static int[] mul (int a[], int b[])  {int alen  = a.length;int blen = b.length;int temp = 0;int len =  alen + blen;int t[] = new int[len];for  (int i = 0; i  <= len - 1; i++)  {t[i] = 0;} for  (int i = 0; i <= alen - 1; i++)  {for  (int  j = 0; j <= blen - 1; j+ +)  {temp = a[i] * b[j];t[j + i] += temp;}}   carry operations with a T array greater than 10 carrybit (t); return t;} /** *  the number represented by the array, carrying the carry operation for each bit  *  @param  a */static void carrybit (int a[] )  {int len = a.length;int temp;for  (int i = 0; i <=  len - 2; i++)  {temp = a[i];if  (temp >= 10)  {a[i]  = temp % 10;a[i + 1] = a[i + 1] + temp /  10;}}} /** *  print Words  *  @param  a */static void printnum (int a[])  {int  len = a.length;int f = 0;for  (int i = len - 1;  i >= 0; i--)  {if  (a[i] > 0) f = 1;if  (f >  0)  {system.out.print (A[i]);}} /** * *  converts a number to a digital representation  *  @param n *  @return  */static int[] dividenumtoarray (int n)  {int bit  = bits (n); int[] array = new int[bit];int i = 0;do {array[i+ +] = n % 10;n = n / 10;}  while  (n > 0); return array;} /** *  returns the number of bits  *  @param  n *  @return  */static int bits (int  n)  {int cnt = 0;while  (n > 0)  {n = n / 10 ; cnt++;} return cnt;} /** *  n factorial  *  @param  n *  @return  */static int[] factorial ( Int n) {int[] result = {1} ;if (n<0)  {system.out.println ("Input error"); Return  null;} if (n ==0) { result = new int[0]; result[0] = 1; return   Result;} Int bit = bits (n); Int temp[] =&nbsP;new int[bit];for (int i=1;i<=n;i++) {Temp = dividenumtoarray (i); Result = mul ( Temp, result);} Return result;}}

The factorial of a larger integer n, because n is larger than the normal type of the factorial of the expression range, using an array of operations (Java implementation)