斐波那契查找法

import java.util.Arrays;

public class FibonacciSearch {
    public static int maxSize = 20;

    //斐波那契数列
    public static int[] fib() {
        int[] f = new int[maxSize];
        f[0] = 1;
        f[1] = 1;
        for (int i = 2; i < maxSize; i++) {
            f[i] = f[i - 1] + f[i - 2];
        }
        return f;
    }
    /* 斐波那契查找
     *  arr 待查找数列
     *  key 待查找元素
     *  return 带查找元素下标
     * */
    public static int fibSearch(int[] arr, int key) {
        int low = 0;
        int high = arr.length - 1;
        int k = 0;//斐波那契下标
        int mid = 0;//存放mid值
        int[] f = fib();
        while (high > f[k] - 1) {
            k++;
        }
        //到目前为止，不足的部分用0来填充
        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;
            if (key < temp[mid]) { //小于则往右
                //递归传参
                high = mid - 1;
                k--;
            } else if (key > temp[mid]) {
                //大于则往右
                low = mid + 1;
                k -= 2;
            } else {
                if (mid <= high) {
                    return mid;
                } else {
                    return high;
                }
            }
        }
        return -1;
    }
}