ACM刷題之HDU————Hat's Fibonacci

Hat's Fibonacci

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 2053 Accepted Submission(s): 802

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 JAVA 大數大法好！ 這題之前一直卡着。原來用高精度來做，但是送出每次都會爆記憶體。于是就放着沒做了。這兩天自學了點JAVA，于是又撿起來。 大數的基本操作就不羅列了，下面是ac代碼： import java.math.BigInteger; import java.util.Scanner; import java.math.*; import java.text.*; public class Main { public static void main(String[] args) { // TODO 自動生成的方法存根 Scanner cin=new Scanner(System.in); int i; BigInteger[] big = new BigInteger[12000]; big[1] = new BigInteger("1"); big[2] = new BigInteger("1"); big[3] = new BigInteger("1"); big[4] = new BigInteger("1"); for(i=5;i<11111;i++) { big[i] =big[i-1].add(big[i-2]); big[i] = big[i].add(big[i-3]); big[i] = big[i].add(big[i-4]); } while(cin.hasNext()) //等同于!=EOF { i=cin.nextInt(); System.out.println(big[i]); } } }