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): 9821    Accepted Submission(s): 3260

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

   
   
   
   

    
    
    
    4203968145672990846840663646


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

大数题目，用java的大数类写的，代码如下：

import java.math.BigInteger;
import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner cin = new Scanner(System.in);
		BigInteger f[]= new BigInteger[10005];
		f[1] = new BigInteger("1");
		f[2] = new BigInteger("1");
		f[3] = new BigInteger("1");
		f[4] = new BigInteger("1");
		for(int i=5;i<=10000;i++)
			f[i]=f[i-1].add(f[i-2].add(f[i-3].add(f[i-4])));
		while(cin.hasNext())
		{
			int n=cin.nextInt();
			System.out.println(f[n]);
		}
	}

}