java练习

 1.6个评委打分,去掉最高和最低,求最后四个评委的均分

//6个评委打分,去掉最高和最低,求最后四个评委的平均分
public class Test4 {
    public static void main(String[] args) {
        //定义一个数组,用来储存评委打分
        double[] scoreArr=getScores();
        for (int i=0;i<scoreArr.length;i++){
            System.out.print(scoreArr[i]);
        }
        //求最大值
        double max=getMax(scoreArr);
        System.out.println("最大值为:"+max);
        //求最小值
        double min=getMin(scoreArr);
        System.out.println("最小值为:"+min);
        //求和
        double sum=getSum(scoreArr);
        System.out.println("sum为:"+sum);
        //求平均值
        double avg=(sum-min-max)/(scoreArr.length-2);
        System.out.println("最终的成绩为:"+avg);

    }
    public static double[] getScores() {
        double[] scores = new double[6];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < scores.length;) {
            System.out.println("请输入评委打分:");
            double score = sc.nextInt();
            if (score >= 0 && score <= 100) {
                scores[i] = score;
                i++;
            } else {
                System.out.println("该评委打分不在范围内,请重新打分");
            }
        }
        return scores;
    }
    public static double getMax(double[] scoreArr){
        double max=scoreArr[0];
        for(int i=0;i<scoreArr.length;i++){
            if(max<scoreArr[i]){
                max=scoreArr[i];
            }
        }
        return max;
    }
    public static double getMin(double[] scoreArr){
        double min=scoreArr[0];
        for(int i=0;i<scoreArr.length;i++){
            if(min>scoreArr[i]){
                min=scoreArr[i];
            }
        }
        return min;
    }
    public static  double getSum(double[] scoreArr){
        double sum=0;
        for(int i=0;i<scoreArr.length;i++){
            sum+=scoreArr[i];
        }
        return sum;
    }
}

 2.数字加密

package com.itheima.tset;

import java.util.Scanner;

//数字加密
//某系统数字加密,先得到每位数
//每位+5,再对10进行求余,最后将所有数字反转,得到新的数.
public class Test5 {
    public static void main(String[] args) {
        int[] arr=new int[4];
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入初始密码:");
        for (int i=0;i<arr.length;i++){
            arr[i]= sc.nextInt();
        }

        int[] NewArr=getPass(arr);
        for (int i=0;i<NewArr.length;i++){
            System.out.print(NewArr[i]+" ");
        }
    }
    public static int[] getPass(int[] arr){
        int[] newArr=new int[arr.length];
        for(int i=0;i<arr.length;i++){
            arr[i]+=5;
            arr[i]=arr[i]%10;
        }
        int index=arr.length;
        for (int i=0;i<newArr.length;i++){
            newArr[i]=arr[index-1];
            index--;
        }
        return newArr;
    }
}

package com.itheima.tset;

import java.util.Scanner;

public class Test6 {
    public static void main(String[] args) {
        System.out.println("请输入初始密码:");
        Scanner sc=new Scanner(System.in);
        int number=sc.nextInt();
        int temp=number;
        int count=0;
        while(number!=0){
            number=number/10;
            count++;
        }
        int[] arr=new int[count];
        while (temp!=0) {
            int ge = temp % 10;
            temp = temp / 10;
            arr[count - 1] = ge;
            count--;
        }
        for (int i=0;i<arr.length;i++){
            System.out.print(arr[i]);
        }
    }
}

3.抽奖(不能有重复奖项) 

package com.itheima.tset;

import java.util.Random;

//抽奖的实现,奖项不能重复
public class Test7 {
    public static void main(String[] args) {
        int[] arr={2,88,188,388,588};
        int[] newArr=new int[arr.length];
        Random r=new Random();

        for (int i=0;i<5;){
            int RandomIndex=r.nextInt(arr.length);
            int prize=arr[RandomIndex];
            boolean flag=contains(newArr,prize);
            if(!flag){
                newArr[i]=prize;
                i++;
            }
        }
        for (int i=0;i< newArr.length;i++){
            System.out.print(newArr[i]+" ");
        }
    }
//判断新的数组内是否有相同的奖项!!!!!!!
    //判断奖项是否已经存在
    public static boolean contains(int[] newArr,int prize){
        for (int i=0;i<newArr.length;i++){
            if(newArr[i]==prize){
                return true;
            }
        }
        return false;
    }
}