二分查找法

import java.util.Arrays;
import java.util.Random;

public class bulubulu {
    public static void main(String[] args) {
        int[] ints = new int[50];
        for (int i = 0; i < ints.length ; i++) {
            ints[i]=new Random().nextInt(100);
        }
        int index = pp(ints,50);
        System.out.println("查找的数在索引为："+index+"的位置");
    }

    public static int pp(int[] ints,int i){
        Arrays.sort(ints);
        int max = ints.length-1;
        int min = 0;
        while (min <= max){
            int half = (min+max)/2;
            if (i == ints[half]) {
                return half;
            }
            if (i>ints[half]){
                min = half+1;
            }
            if (i<ints[half]){
                max = half-1;
            }
        }
        return -1;

    }
}