【基础算法】- 个人认为最快的 Fibonacci 程序

时间：2014-06-03 07:24:25 收藏：0 阅读：221

public class Fibonacci {
     
    private 
static Map<Long,Long> map = new 
HashMap<Long,Long>(); 
    static{
        map.put(0L, 1L);
        map.put(1L, 1L);
    }
     
    public 
static void main(String[] args) {
         
        long 
t = System.currentTimeMillis();
        Fibonacci fi = new 
Fibonacci();
        System.out.println(fi.cal(36L,map));
        System.out.println(System.currentTimeMillis() - t);
        System.out.println();
        t = System.currentTimeMillis();
        fi = new 
Fibonacci();
        System.out.println(fi.cal(36L));
        System.out.println(System.currentTimeMillis() - t);
    }
     
    public 
Long cal(Long n, Map<Long,Long> map){
         
        if(map.get(n) != null){
            return 
map.get(n);
        }else{
            long 
i = cal(n-1,map) + cal(n-2,map);
            map.put(n, i);
            return 
i;
        }
    }

【基础算法】- 个人认为最快的 Fibonacci 程序,布布扣,bubuko.com