模板

public class BinarySearch {

    // 检查x是否满足某种性质
    public static boolean check(double x) {
        // 实现具体的检查逻辑
        return false; // 这里仅为示例，实际根据需求修改
    }

    public static double bsearch_3(double l, double r) {
        final double eps = 1e-6;   // 精度要求
        while (r - l > eps) {
            double mid = (l + r) / 2;
            if (check(mid)) {
                r = mid;
            } else {
                l = mid;
            }
        }
        return l;
    }

    public static void main(String[] args) {
        double result = bsearch_3(0, 100);  // 示例调用
        System.out.println("结果: " + result);
    }
}

例题：求数的平方根

package base;

import java.util.Scanner;

public class Sqrt_demo {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //求x的平方根
        double x = sc.nextDouble();
        sqrt(x);

    }
    public static void sqrt(double x){
        double l =0,r = x;
        while (r-l>1e-8){
            double mid = (l+r)/2;
            if (mid*mid>x) r=mid;
            else l = mid;
        }
        System.out.println(String.format("%.6f",l));
    }
}