案例 打分，加密，拷贝

打分案例

package com.lzk.test;

import java.util.Scanner;
public  class test {
    public static void main(String[] args) {

        //评委打分案例，输入五位评委打分，去掉最高分和最低分，求平均分
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入五位评委打分，用空格分隔：");
        String input = scanner.nextLine();
        String[] scores = input.split(" ");
        int sum = 0;
        int max = Integer.MIN_VALUE;//转成int
        int min = Integer.MAX_VALUE;
        for (int i = 0; i < scores.length; i++) {
            int score = Integer.parseInt(scores[i]);
            if (score > max) {
                max = score;
            }
            if (score < min) {
                min = score;
            }
            sum += score;
        }
        System.out.println("去掉最高分和最低分后，平均分为：" + 1.0* (sum - max - min) / (scores.length - 2));//1.0可以计算出小数
    }
}

加密

package com.lzk.test;

import java.util.Scanner;
public  class test {
    //对四个数字进行加密处理，，首先+5，然后%10，然后反转，最后输出结果
    public static void main(String[] args) {
        //接受一个千位数
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入一个四位数：");//1983
        int number = scanner.nextInt();
        encrypt(number);
    }

    //将这个千位数存放在数组，遍历数组，对每个数字进行加密处理
    public static void encrypt(int number) {
        int[] numbers = split(number);
        for (int i = 0; i < numbers.length; i++) {
            numbers[i] = (numbers[i] + 5) % 10;
            System.out.println("number[" + i +"] = " + numbers[i]);//8346

        }
        reverse(numbers);
        String result = "";
        for (int i = numbers.length - 1;  i >= 0; i--) {
            result += numbers[i];
        }
        System.out.println("加密结果：" + result);//8346
    }

    //将一个四位数分割成数组
    public static int[] split(int number) {
        int[] numbers = new int[4];
        for (int i = 0; i < 4; i++) {
            numbers[i] = number % 10;
            number /= 10;
            System.out.println("numbers[" + i +"] = " + numbers[i]);//3891
        }
        return numbers;
    }

    public static void reverse(int[] numbers) {
        int temp;
        for (int i = 0, j = numbers.length - 1; i < j; i++, j--) {
            temp = numbers[i];
            numbers[i] = numbers[j];
            numbers[j] = temp;
        }
    }
}

拷贝数组

package com.lzk.test;

import java.util.Scanner;
public  class test {
    //拷贝数组
    public static void copyArray(int[] arr){
        int[] newArr = new int[arr.length];
        for(int i=0;i<arr.length;i++){
            newArr[i] = arr[i];
        }
        System.out.println("拷贝后的数组为：");
        for(int i=0;i<newArr.length;i++){
            System.out.print(newArr[i]+" ");
        }
    }
//不能用System.out.println()输出数组，因为数组元素之间有空格，会导致输出不正常
    //int[] newArr = arr,因为这只是把地址指向了，并没有拷贝数组元素
    //输入数组
    public static void inputArray(int[] arr){
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入数组元素：");
        for(int i=0;i<arr.length;i++){
            arr[i] = scanner.nextInt();
        }
        System.out.println("输入的数组为：");
        for(int i=0;i<arr.length;i++){
            System.out.print(arr[i]+" ");
        }
    }

}