Java-黑马Java学习作业-day07综合练习

学习视频链接：https://www.bilibili.com/video/BV17F411T7Ao

文章目录

练习一：飞机票
练习二：打印素数
练习三：验证码
练习四：复制数组
练习五：评委打分
练习六：数字加密
练习七：数字解密
练习八：抽奖
- 解法一:
- 解法二：
练习九：双色球

练习一：飞机票

需求:

机票价格按照淡季旺季、头等舱和经济舱收费、输入机票原价、月份和头等舱或经济舱。

按照如下规则计算机票价格：旺季（5-10月）头等舱9折，经济舱8.5折，淡季（11月到来年4月）头等舱7折，经济舱6.5折。

代码示例：

import java.util.Scanner;/*** @ClassName: codePractice01* @Author: Kox* @Data: 2023/1/13* @Sketch:*/
public class codePractice01 {public static void main(String[] args) {Scanner sc = new Scanner(System.in);System.out.println("请输入飞机原价格：");int price = sc.nextInt();System.out.print("请输入月份：");int month = sc.nextInt();System.out.print("请输入舱位：(0是头等，1是经济）");int level = sc.nextInt();if (month >= 5 && month <= 10) {price = getPrice(price, level, 0.9, 0.85);} else if ((month >= 1 && month <= 4) || (month >= 11 && month <= 12)) {price = getPrice(price, level, 0.7, 0.65);} else {System.out.println("月份输入错误");}System.out.println(price);}public static int getPrice(int price, int level , double v0, double v1) {if (level == 0) {price = (int) (price * v0);} else if (level == 1){price = (int) (price * v1);} else {System.out.println("没有这个舱位！");}return price;}
}

练习二：打印素数

判断101~200之间有多少个素数，并输出所有素数。

备注：素数就是质数

代码示例：

/*** @ClassName: cn.kox.practice.codePractice02* @Author: Kox* @Data: 2023/1/13* @Sketch: 找质数*/
public class codePractice02 {public static void main(String[] args) {int count = 0;for (int i = 101; i <= 200; i++) {boolean flag = true;for (int j = 2; j < i; j++) {if (i % j == 0) {flag = false;break;}}if (flag) {System.out.print(i + "\t");count++;}}System.out.println("\n有" + count + "个质数。");}
}

练习三：验证码

需求：

定义方法实现随机产生一个5位的验证码

验证码格式：

长度为5

前四位是大写字母或者小写字母

最后一位是数字

代码示例：

import java.util.Arrays;
import java.util.Random;/*** @ClassName: codePractice03* @Author: Kox* @Data: 2023/1/13* @Sketch: 开发验证码*/
public class codePractice03 {public static void main(String[] args) {char[] letter = new char[52];for (int i = 0; i < letter.length; i++) {if (i <= 25) {letter[i] = (char)(97 + i);} else {letter[i] = (char)(65 + i - 26);}}Random r = new Random();
//        String verify = "";char[] verify = new char[5];for (int i = 0; i <= 4; i++) {int index = r.nextInt(letter.length - 1) + 1;if (include(verify, letter, index)) {verify[i] = letter[index];}if (i == 4) {index = r.nextInt(10) + 48;verify[i] = (char) index;}}System.out.println(Arrays.toString(verify));}public static boolean include(char[] brr, char[] arr, int num) {for (int i = 0; i < brr.length - 1; i++) {if (brr[i] == arr[num]) {return false;}}return true;}
}

练习四：复制数组

需求：

把一个数组中的元素复制到另一个新数组中去。

代码示例：

import java.util.Arrays;/*** @ClassName: codePractice04* @Author: Kox* @Data: 2023/1/13* @Sketch: 数组元素复制*/
public class codePractice04 {public static void main(String[] args) {int[] arr = {1, 2, 3, 5, 6, 99, 100};int[] brr = new int[arr.length];for (int i = 0; i < arr.length; i++) {brr[i] = arr[i];}System.out.println(Arrays.toString(brr));}
}

练习五：评委打分

需求 :

在唱歌比赛中，有6名评委给选手打分，分数范围是[0 - 100]之间的整数。选手的最后得分为：去掉最高分、最低分后的4个评委的平均分，请完成上述过程并计算出选手的得分。

代码示例：

import java.util.Arrays;
import java.util.Random;/*** @ClassName: codePractice05* @Author: Kox* @Data: 2023/1/13* @Sketch: 评委打分*/
public class codePractice05 {public static void main(String[] args) {int[] arr = new int[6];     // 评委的分数Random r = new Random();for (int i = 0; i < arr.length; i++) {int rScore = r.nextInt(101);arr[i] = rScore;}int score = 0;for (int i = 0; i < arr.length; i++) {score += arr[i];}int maxScore = getMax(arr);int minScore = getMin(arr);double endScore = (double) (score - maxScore - minScore) / (arr.length - 2);System.out.println(Arrays.toString(arr));System.out.println("去掉一个最高分：" + maxScore + "，去掉一个最低分：" + minScore + "，最后得分" + endScore + "分儿。");}public static int getMax(int[] arr) {int maxScore = arr[0];for (int i = 1; i < arr.length; i++) {if (maxScore < arr[i]) {maxScore = arr[i];}}return maxScore;}public static int getMin(int[] arr) {int minScore = arr[0];for (int i = 1; i < arr.length; i++) {if (minScore > arr[i]) {minScore = arr[i];}}return minScore;}
}

练习六：数字加密

需求：

某系统的数字密码（大于0），比如1983，采用加密方式进行传输。

规则如下：

先得到每位数，然后每位数都加上5 , 再对10求余，最后将所有数字反转，得到一串新数。

举例：

     1   9   8   3
+5     6   14  13  8
%10     6   4   3   8
反转     8   3   4   6
加密后的结果就是：8346

代码示例：

/*** @ClassName: codePractice06* @Author: Kox* @Data: 2023/1/14* @Sketch: 数字加密*/
public class codePractice06 {public static void main(String[] args) {int[] arr = {1, 9 , 8 , 3};int number = 0;for (int i = arr.length-1; i >= 0; i--) {number = number * 10 + getNum(arr[i]);}System.out.print("加密后的结果就是：" + number);}public static int getNum(int num) {num = (num + 5) % 10;return num;}}

练习七：数字解密

把上一题加密之后的数据进行解密

代码示例：

/*** @ClassName: codePractice07* @Author: Kox* @Data: 2023/1/14* @Sketch: 数字解密*/
public class codePractice07 {public static void main(String[] args) {int[] arr = {8, 3, 4, 6};int number = 0;for (int i = arr.length-1; i >= 0; i--) {number = number * 10 + getNum(arr[i]);}System.out.println(number);}public static int getNum(int num) {num = (num + 5) % 10;return num;}
}

练习八：抽奖

需求：

一个大V直播抽奖，奖品是现金红包，分别有{2, 588 , 888, 1000, 10000}五个奖金。请使用代码模拟抽奖，打印出每个奖项，奖项的出现顺序要随机且不重复。打印效果如下：（随机顺序，不一定是下面的顺序）

888元的奖金被抽出
588元的奖金被抽出
10000元的奖金被抽出
1000元的奖金被抽出
2元的奖金被抽出

解法一:

import java.util.Arrays;
import java.util.Random;/*** @ClassName: codePractice08* @Author: Kox* @Data: 2023/1/14* @Sketch: 抽奖*/
public class codePractice08 {public static void main(String[] args) {int[] arr = {2, 588, 1000, 10000};Random r = new Random();for (int i = 0; i < arr.length; i++) {int index = r.nextInt(arr.length);int temp = arr[i];arr[i] = arr[index];arr[index] =temp;}System.out.println(Arrays.toString(arr));}}

解法二：

import java.util.Random;/*** @ClassName: codeHomework11* @Author: Kox* @Data: 2023/1/10* @Sketch: 题目11*/
public class codeHomework11 {public static void main(String[] args) {int[] arr = {2, 588, 1000, 10000};int[] brr = new int[arr.length];Random r = new Random();int flag = 0;while (flag < arr.length) {int index = r.nextInt(arr.length);if (returnNum(brr, arr[index])) {brr[flag] = arr[index];System.out.println(brr[flag] + "元的奖金被抽出");flag++;}}}public static boolean returnNum(int[] arr, int num) {for (int i = 0; i < arr.length; i++) {if (arr[i] == num) {return false;}}return true;}
}

练习九：双色球

代码示例:

import java.util.Arrays;
import java.util.Random;
import java.util.Scanner;/*** @ClassName: codePractice09* @Author: Kox* @Data: 2023/1/14* @Sketch: 双色球系统*/
public class codePractice09 {public static void main(String[] args) {int[] red = new int[33];red = getArr(red);int[] blue = new int[16];blue = getArr(blue);int[] luckyArr = new int[7];    // 抽出的中奖数组Random r = new Random();int index = 0;while (index < luckyArr.length) {int redIndex = r.nextInt(red.length);if (getNum(luckyArr, red[redIndex])) {luckyArr[index] = red[redIndex];index++;}if (index == luckyArr.length - 1) {int blueIndex = r.nextInt(blue.length);luckyArr[index] = blue[blueIndex];index++;}}// System.out.println("本次奖池号码为：" + Arrays.toString(luckyArr));int[] userArr = new int[luckyArr.length];   // 用户输入的号码Scanner sc = new Scanner(System.in);int count = 1;while (count <= userArr.length) {if (count == userArr.length) {System.out.print("输入蓝色球的号码：");int num = sc.nextInt();if (num >= blue[0] && num <= blue[blue.length-1]) {userArr[count-1] = num;count++;} else {System.out.println("奖池没有该数字！");}} else {System.out.print("输入红色球的第" + count + "个数字：");int num = sc.nextInt();if (num >= red[0] && num <= red[red.length-1]) {if (getNum(userArr,num)) {userArr[count-1] = num;count++;} else {System.out.println("数字输入重复！");}} else {System.out.println("奖池没有该数字！");}}}int redCount = 0;int blueCount = 0;for (int i = 0; i < userArr.length; i++) {if (i == userArr.length-1) {if (luckyArr[i] == userArr[i]) {blueCount++;}} else {if (luckyArr[i] == userArr[i]) {redCount++;}}}System.out.println("本次奖池号码为：" + Arrays.toString(luckyArr));System.out.println("你竞猜的号码为：" + Arrays.toString(userArr));System.out.println("红蓝中将次数分别是："+ redCount + ":" + blueCount);switch (redCount) {case 0,1,2 -> System.out.println(blueCount != 0 ? "六等奖5元" : redCount != 0 ? "六等奖：5元" : "无奖");case 3 -> System.out.println(blueCount != 0 ? "五等奖：10元" : "六等奖：5元");case 4 -> System.out.println(blueCount != 0 ? "四等奖：200元" : "五等奖：10元");case 5 -> System.out.println(blueCount != 0 ? "三等奖：3000元" : "四等奖：200元");case 6 -> System.out.println(blueCount != 0 ? "一等奖：最高1000万" : "二等奖：最高500万");}}public static int[] getArr(int[] arr) {for (int i = 0; i < arr.length; i++) {arr[i] = i + 1;}return arr;}public static boolean getNum(int[] arr, int num) {for (int i = 0; i < arr.length; i++) {if (arr[i] == num) {return false;}}return true;}}