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 Description

A 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 Fibonacci number.

 

Input

Each line will contain an integers. Process to end of file.

 

Output

For 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.

 

<span style="font-size:24px;">import java.math.BigInteger;import java.util.Scanner;public class yiu {public static void main(String[] args) {Scanner cin=new Scanner(System.in);BigInteger[] a = new BigInteger[10002];// 定义数组a[1]=BigInteger.ONE;   //相当于a[1]=1;a[2]=BigInteger.ONE;a[3]=BigInteger.ONE;a[4]=BigInteger.ONE;for(int i=5;i<a.length;i++){a[i]=a[i-1].add(a[i-2].add(a[i-3].add(a[i-4])));}while (cin.hasNext()) // 多重输入</span>

<span style="font-size:24px;">                <span style="font-family:Arial, Helvetica, sans-serif;">{</span></span>

<span style="font-size:24px;">int n=cin.nextInt();System.out.println(a[n]);}}}</span>