查找算法----斐波那契查找

package 查找算法;

import java.util.Arrays;

//斐波那契查找
public class FibonacciSearch {
    public static void main(String[] args) {
        int [] arr={1,5,12,21,30,32,55,68,80,89,90,99};
        int key=30;
        int index=fibonacciSearch(arr,key);
        System.out.println("index="+index);
    }

    private static int fibonacciSearch(int[] arr, int key) {
       int f[]=getFiboacci();
       int low=0;
       int high=arr.length-1;
       int mid=0;
       int k=0;
       while (high>f[k]-1){
           k++;
       }
       int [] temp= Arrays.copyOf(arr,f[k]);
       for (int i=high+1;i<temp.length;i++){
           temp[i]=arr[high];
       }
       while (low<=high){
           mid=low+f[k-1]-1;
           System.out.println("mid="+mid);
           if(key<temp[mid]){
               high=mid-1;
               k-=1;
           }else if (key>temp[mid]){
               low=mid+1;
               k-=2;
           }else {
               if(mid<=high){
                   return mid;
               }else {
                   return high;
               }
           }
       }
       return mid;
    }

    private static int[] getFiboacci() {
        int []f=new int[20];
        f[0]=1;
        f[1]=1;
        for (int i=2;i<f.length;i++){
            f[i]=f[i-1]+f[i-2];
        }
        return f;
    }

}

執行結果

mid=7
mid=4
index=4