HDU 1250: hat's Fibonacci

Hat's Fibonacci Time Limit: 2000/1000 MS (Java/others) memory limit: 65536/32768 K (Java/Others)
Total submission (s): 6925 accepted submission (s): 2279


Problem descriptiona Fibonacci sequence is calculated by adding the previous two members the sequence, with the first two members being both 1.
F (1) = 1, F (2) = 1, F (3) = 1, F (4) = 1, F (n> 4) = f (n-1) + f (n-2) + f (n-3) + f (n-4)
Your task is to take a number as input, and print that maid number.
 
Inputeach line will contain an integers. process to end of file.
 
Outputfor each case, output the result in a line.
Sample Input

100

 
Sample output

4203968145672990846840663646Note:No generated Fibonacci number in excess of 2005 digits will be in the test data, ie. F(20) = 66526 has 5 digits.

import java.math.BigInteger;     import java.util.Scanner;       public class Main {             public static void main(String[] args) {             Scanner cin = new Scanner((System.in));             int  n;          BigInteger[] f = new BigInteger[10000];          f[1] = BigInteger.ONE;          f[2] = BigInteger.ONE;          f[3] = BigInteger.ONE;          f[4] = BigInteger.ONE;          for(int i=5; i<f.length;i++)               f[i] = f[i-1].add(f[i-2].add(f[i-3].add(f[i-4])));          while(cin.hasNext()){              n = cin.nextInt();              System.out.println(f[n]);          }      }     }