BigInteger Factorial Dynamic Programming

bigintfactorial.java

import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;
class bigintfactorial
 {
     public static Map<BigInteger,BigInteger> nf;
	public static void main (String[] args)
	 {
	 Scanner scr=new Scanner(System.in);
	 int n=Integer.parseInt(scr.nextLine());
	 List numbers=new ArrayList<BigInteger>();
	 for(int i=0;i<n;i++){
	     numbers.add(BigInteger.valueOf(Integer.parseInt(scr.nextLine())));
	 }
	 nf=new HashMap<BigInteger,BigInteger>();
	 nf.put(BigInteger.ONE,BigInteger.ONE);
	 for(int i=0;i<numbers.size();i++){
	     System.out.println(fact((BigInteger)numbers.get(i)));
	 }
	 }
	 
	 public static BigInteger fact(BigInteger x){
	     if(nf.containsKey(x)) {
	         return nf.get(x);
	     } else {
	         return cs(x);//compute and store
	     }
	 }
	 public static BigInteger cs(BigInteger x){
	     if(nf.containsKey(x.subtract(BigInteger.ONE))) {
	         BigInteger v=nf.get(x.subtract(BigInteger.ONE)).multiply(x);
	         nf.put(x,v);
	         return v;
	     }else {
	         return x.multiply(cs(x.subtract(BigInteger.ONE)));
	     }
	 }
}