编程实现

自由落体，100m高，每次返回一半高度，弹跳10次，求经过的路程？小球最后高度？

package com.fan.test;

public class GameDrop {
    public static void main(String[] args) {
        double height =100;
        drop(height);
    }
    public static void drop(double height){
        double sum =height;
        for (int i = 0; i < 10; i++) {
            height/=2;
            if(i == 9){
                sum = sum + height;
            }else{
                sum = sum + height*2;
            }
        }
        System.out.println("小球经过的路程："+sum);
        System.out.println("小球最后的高度："+height);
    }
}

编程实现：字符串反转

• 这里我们借助StringBuffer的reserve()方法实现字符串倒转

package com.fan.test.String.StringBuffer;

public class ReverseDemo {
    public static void main(String[] args) {
          String str = "fanwenqian";
          System.out.println(reverseStr(str));
    }
    public static String reverseStr(String str){
           StringBuffer sbf = new StringBuffer(str);
           return sbf.reverse().toString();
    }
}

字符串转int类型

int a =Integer.parseInt("string");

冒泡排序算法

实现数组从小到大排列

package com.fan.test.sort;

import java.util.Arrays;

public class DemoSort {
    public static void main(String[] args) {
        //冒泡排序算法
        int[] numArrary = new int[]{1,5,8,7,2,3,9,4};
        for (int i = 0; i < numArrary.length-1; i++) {
            for (int j = 0; j < numArrary.length-1-i; j++) {
                if(numArrary[j]>numArrary[j+1]){
                    int temp = numArrary[j];
                    numArrary[j] = numArrary[j+1];
                    numArrary[j+1] = temp;
                }
            }
        }
        System.out.println(Arrays.toString(numArrary));
    }
}