插值查找

import java.util.ArrayList;

public class InsertValueSearch {

    public static void main(String[] args) {
        int arr[] = {1, 2, 3, 11, 12, 13, 18, 19, 20};
        ArrayList resIndexList = insertValueSearch(arr, 0, arr.length - 1, 11);
        System.out.println(resIndexList);
    }

    public static ArrayList<Integer> insertValueSearch(int[] arr, int left, int right, int findVal) {
        if (left > right) {
            return new ArrayList<Integer>();
        }
        int mid = left + (right - left) * (findVal - arr[left]) / (arr[right] - arr[left]);//差值查找mid
        int midVal = arr[mid];
        if (findVal > midVal) {
            return insertValueSearch(arr, mid + 1, right, findVal);
        } else if (findVal < midVal) {
            return insertValueSearch(arr, left, mid - 1, findVal);
        } else {
            ArrayList<Integer> resIndexlist = new ArrayList<Integer>();
            int temp = mid - 1;
            while (true) {
                if (temp < 0 || arr[temp] != findVal) {
                    break;
                }
                resIndexlist.add(temp);
                temp -= 1;//往左移动
            }
            resIndexlist.add(mid);
            temp = mid + 1;
            while (true) {
                if (temp > arr.length - 1 || arr[temp] != findVal) {
                    break;
                }
                resIndexlist.add(temp);
                temp += 1;//往右移动
            }
            return resIndexlist;
        }
    }
}