插值查找和斐波拉契查找

插值查找

package com.dai.search;

import java.util.Arrays;

public class InsertValueSearch {

    public static void main(String[] args) {
        int[] arr = new int[100];
        for(int i=0;i<100;i++) {
            arr[i] = i+1;
        }
        int index = insertValueSearch(arr, 0, arr.length-1, 51);
        System.out.println("index=" + index);
        //System.out.println(Arrays.toString(arr));
    }
    /**
     * 
     * @param arr : 数组
     * @param left ：左索引
     * @param right：右索引
     * @param findVal ：待查找的值
     * @return ： 返回下标
     */
    public static int insertValueSearch(int[] arr, int left, int right, int findVal) {
        if(left>right || findVal<arr[left] || findVal>arr[right]) {
            return -1;
        }
        // 插值查找只有此处mid取值与二分查找不同
        int mid = left + (findVal-arr[left])/(arr[right]-arr[left])*(right-left);
        if(findVal<arr[mid]) {
            return insertValueSearch(arr, left, mid-1, findVal);
        }else if(findVal > arr[mid]) {
            return insertValueSearch(arr, mid+1, right, findVal);
        }else {
            return mid;
        }
    }

}

斐波拉契查找

package com.dai.search;

import java.util.Arrays;

public class FibonacciSearch {
    public static int maxsize = 20;

    public static void main(String[] args) {
        int[] arr = {1,3,4,56,89,100,145,456,1000,1234};
        //System.out.println(Arrays.toString(fib()));
        int index = fibSearch(arr, 1234);
        System.out.println(index);
    }
    //生成斐波那契数列
    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;
    }
    public static int fibSearch(int[] arr, int key) {
        int[] f = fib();
        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<f[k]-1;i++) {
            temp[i] = arr[high];
        }
        while(low <= high) {
            mid = low + f[k-1] - 1;
            if(key>temp[mid]) {
                k-=2;
                low = mid +1;
            }
            if(key<temp[mid]) {
                k-=1;
                high = mid -1;
            }
            if(key==temp[mid]) {
                if(mid<=high)
                    return mid;
                else {
                    return high;
                }
            }
        }
        return -1;
    }

}