查找-斐波那契

public class TestObject {
public static void main(String[] args) {
int[] arr = {1,3,5,6,8,10,11,15,66,100};
int i = fibonacciSearch(arr, 11);
System.out.println(i);

}

/**
* 得到斐波那契数列
* @return
*/
public static int[] fib() {
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;
}

/**
* 斐波那契查找算法
* @param arr
* @param value
* @return
*/
public static int fibonacciSearch(int[] arr, int value) {
//查找界限
int low = 0;
int high = arr.length - 1;
//存放分割数的下标和值
int k = 0;
int mid = 0;
//得到斐波那契数列
int[] fib = fib();
//获得k分割数的下标
while (high > fib[k] - 1) {
k++;
}
//对数组扩容
int[] temp = Arrays.copyOf(arr, fib[k]);
//填充扩容数组
for (int i = high + 1; i < temp.length; i++) {
temp[i] = arr[high];
}
//当左界大于等于右界时退出
while (low <= high) {
mid = low + fib[k - 1] - 1;
if (value < temp[mid]) {
//查找的数在左边
high = mid - 1;
//f[k] = f[k-1] + f[k-2],位于左半段时,下次判定mid时k应该-1
k--;
} else if (value > temp[mid]) {
//查找的数在右边
low = mid + 1;
//f[k] = f[k-1] + f[k-2],位于右半段时,下次判定mid时k应该-2
k -= 2;
} else {
//找到了
if (mid <= high) {
return mid;
} else {
//当mid位于扩容的数组中时，返回最大值
return high;
}
}
}
//没找到
return -1;
}
}