package text.java;

public class test {

    //递归实现二分查找
    public static int binarySearch(int[] dataset,int data,int beginIndex,int endIndex){
        int midIndex = (beginIndex+endIndex)/2;
        if(data <dataset[beginIndex]||data>dataset[endIndex]||beginIndex>endIndex){
            return -1;
        }
        if(data <dataset[midIndex]){
            return binarySearch(dataset,data,beginIndex,midIndex-1);
        }else if(data>dataset[midIndex]){
            return binarySearch(dataset,data,midIndex+1,endIndex);
        }else {
            return midIndex;
        }
    }

    public static void main(String[] args) {
        int[] arr = { 6, 19, 33, 87, 3, 23, 9, 561 };
        int a;
        a=binarySearch(arr,561,0,arr.length-1);
        if(a==-1){
            System.out.println("未找到");
        }
        else System.out.println("561  "+"递归查找index="+a);

    }
}