javaaaa

 1 飞机票

代码实现：

import java.util.Scanner;
public class F1 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("请输入票价：  ");double jia = input.nextDouble();System.out.print("请输入月份：  ");int yue = input.nextInt();System.out.print("请输入你所坐飞机舱（经济舱或头等舱）  ");String can = input.next();methodjia(jia,yue,can);}private static void methodjia(double jia, int yue, String can) {if (yue>=5 && yue<=10){if (can.equals("经济舱")){jia=jia*0.85;}else if(can.equals("头等舱")) {jia = jia * 0.9;}elseSystem.out.println("输入错误");return;} else if((yue>10 && yue<=12) || (yue<5 && yue>0)){if (can.equals("头等舱")){jia=jia*0.7;}else if(can.equals("经济舱")){jia=jia*0.65;}elseSystem.out.println("输入错误");return;} else if(yue<0||yue>12){System.out.println("错误");return;}System.out.println(jia);}
}

2 生成一个五位数验证码

代码实现：

import java.util.Random;public class Yzm {public static void main(String[] args) {char []arr = new char[52];Random rand = new Random();for (int i = 0; i < 26; i++) {arr[i] = (char) (65+i);}for (int i = 0; i <26; i++) {arr[i+26] = (char) (97+i);}String s ="";for (int i = 0; i < 4; i++) {char k = arr[rand.nextInt(52)];s=s+k;}int i = rand.nextInt(10);s=s+i;System.out.println(s);}
}

3 数字加密

代码实现：

import java.util.Scanner;public class Jm {public static void main(String[] args) {int num = new Scanner(System.in).nextInt();//输入一个数组jiami(intToArray3(num));//方法调用}private static void jiami(int[] arr) {//加密方法每个位数+5，每个位数对10取模，再倒序for (int i = 0; i < arr.length; i++) {arr[i]+=5;}for (int i = 0; i < arr.length; i++) {arr[i]%=10;}for (int i = 0,j = arr.length-1; i < j; i++,j--) {int temp = arr[i];arr[i] = arr[j];arr[j] = temp;}int num = 0;for (int i = 0; i < arr.length; i++) {num= num*10+arr[i];}System.out.println(num);}private static int[] intToArray3(int num){int len = String.valueOf(num).length();//得到这个数的长度以便创建数组int[] resultArray = new int[len];//创建数组while (num != 0){//给数组一一赋值resultArray[len-1] = num % 10;num = num / 10;len--;}return resultArray;//返回位数组成的数组}
}

4 数字解密

import java.util.*;public class Jiemi {public static void main(String[] args) {int num = new Scanner(System.in).nextInt();jie(int01(num));}private static void jie(int[] arr){for (int i = 0,j=arr.length-1; i < j; i++,j--) {int temp = arr[i];arr[i] = arr[j];arr[j] = temp;}for (int i = 0; i < arr.length; i++) {if (arr[i]+10<15){arr[i] = arr[i]+10;}}
//        4  3  2  1  0  9 8 7 6 5
//        14 13 12 11 10 9 8 7 6 5
//        9  8   7  6 5  4 3 2 1 0for (int i = 0; i < arr.length; i++) {arr[i]-=5;}int shuchu = 0;for (int i = 0; i < arr.length; i++) {shuchu= shuchu*10+arr[i];}System.out.println(shuchu);}private static int[] int01(int num){int len = String.valueOf(num).length();int[] arr = new int[len];while  (num!=0){arr[len-1] = num%10;num/=10;len--;}return arr;}
}

5 抢红包

User类创建

public class User {private String name;private int money;public User(){}public User(String name,int money){this.name=name;this.money=money;}public void show(){System.out.println("Name:"+name+" Money:"+money);}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getMoney() {return money;}public void setMoney(int money) {this.money = money;}
}​

Manage类

import java.util.ArrayList;public class Manager extends User{public Manager(String name, int money) {super(name, money);}public Manager() {super();}
//需要一个集合用来存储发红包的个数以及各个金额public ArrayList<Integer> List(int totalmoney,int count){//发的钱ArrayList<Integer> list = new ArrayList<>();int leftmoney = super.getMoney();//群主总共的钱if(leftmoney < totalmoney) return list;//群主没那么多钱int averagemoney = totalmoney/count;//平均每个人int modemoney = totalmoney%count;//除不尽的余数加在list最后一个for(int i = 0 ; i < count-1 ; i++){list.add(averagemoney);}super.setMoney(leftmoney - totalmoney);//群主剩的钱list.add(modemoney+averagemoney);return list;//返回红包集合}
}

Member类

import java.util.ArrayList;
import java.util.Random;public class Member extends User{public Member() {super();}public Member(String name, int money) {super(name, money);}public void receive(ArrayList<Integer> list){int random = new Random().nextInt(list.size());//随即索引int num = list.remove(random);//将这个数去除，并且取出int money = super.getMoney()+num;//把钱加上super.setMoney(money);//更新前的金额}
}

调用

import java.util.ArrayList;
import java.util.Scanner;public class Using {public static void main(String[] args) {Member A= new Member("贤哥",0);Member B = new Member("超哥",0);Member C = new Member("小哥",0);Manager qun = new Manager("群主",10000);System.out.println("原来的钱");qun.show();A.show();B.show();C.show();System.out.println("================");System.out.println("你想发多少");int F = new Scanner(System.in).nextInt();ArrayList<Integer> list = qun.List(F,3);A.receive(list);B.receive(list);C.receive(list);qun.show();A.show();B.show();C.show();}
}

运行结果：

5 双色球系统

代码实现：

package itheima;import java.util.Scanner;
import java.util.Random;public class seven {public static void main(String[] args) {int [] arr = creatarr();int [] arr1 = maicaipiao();jiage(find(arr,arr1),zuihouyige(arr,arr1));}private static void jiage(int num,int lannum){int hongnum = num-lannum;if (hongnum>=0 && lannum==1 &&hongnum<3){System.out.println("恭喜中奖5元");}else if ((hongnum==4&&lannum==0)||(hongnum==3 && lannum==1)){System.out.println("恭喜中奖10元");}else if ((hongnum==4&&lannum==1)||(hongnum==5 && lannum==0)){System.out.println("恭喜中奖200元");} else if(hongnum==5 && lannum==1){System.out.println("恭喜中奖3000元");}else if(hongnum==6 && lannum==0){System.out.println("恭喜中奖500 0000元");} else if (hongnum==6 && lannum==1) {System.out.println("恭喜中奖1000 0000元");}elseSystem.out.println("一分钱没中");}private static int zuihouyige(int [] arr1,int [] arr2){int lannum=0;if (arr1[6]==arr2[6]){lannum=1;}return lannum;}private static int[] maicaipiao(){Scanner P = new Scanner(System.in);//int[] arr = new int[]{P.nextInt(),P.nextInt(),P.nextInt(),P.nextInt(),P.nextInt(),P.nextInt(),P.nextInt()};int[] arr = new int[7];for (int i = 0; i < 6;) {System.out.println("输入第"+(i+1)+"个数：");int num = P.nextInt();if (num >0 && num<34) {if (isPrime(arr,num)){arr[i] = num;i++;}elseSystem.out.println("已经存在");}elseSystem.out.println("输入范围错误");}System.out.println("输入第7个数：");while(true){int num7= P.nextInt();if (num7>0 && num7<17) {arr[6] = num7;for (int i : arr) {System.out.print(i+" ");}System.out.println(" ");return arr;}elseSystem.out.println("范围错误");}}private static int[] creatarr() {int[] arr = new int[7];//七色球Random rand = new Random();for (int i = 0; i < arr.length-1;) {int suinum = rand.nextInt(33)+1;//前六个数1-33if (isPrime(arr, suinum)) {arr[i] = suinum;i++;}}arr[arr.length-1] = rand.nextInt(16)+1;//第七个数1-16return arr;}private static boolean isPrime(int []arr,int n) {//是不是已经出现没有返回truefor (int i : arr) {if (n==i){return false;}}return true;}private static int find(int[] arr1, int[] arr2) {//多少个相同的int i = 0, j = 0;int count = 0;while (i < arr1.length && j < arr2.length) {if (arr1[i] == arr2[j]) {count++;i++;  // 移动 arr1 的指针j++;  // 移动 arr2 的指针} else if (arr1[i] < arr2[j]) {i++;} else {j++;}}return count;}
}

6 用户登录

代码实现

用户名三次机会出错退出系统。

用户名正确进入系统输入密码，密码三次错误锁定用户。

import java.util.Scanner;public class User {public static void main(String[] args) {String Username = "anxian";String UserPassword = "123456";Scanner sc = new Scanner(System.in);String username = null;int num = 0;while (num < 3) {System.out.println("输入你的用户名：");username = sc.nextLine();if (username.equals(Username)) {break;}else {num++;System.out.println("用户名错误，你还有"+(3-num)+"次机会");}}if (username.equals(Username)) {for (int i = 0; i < 3; i++) {System.out.println("输入你的密码:");String password = sc.nextLine();if (password.equals(UserPassword)) {System.out.println("登陆成功");break;} else {System.out.println("信息错误还有" + (2 - i) + "次机会");if (2-i == 0){System.out.println("用户"+Username+"被锁定，请联系客服。");}}}}}
}

7 金额转换

import java.util.Scanner;public class abc {public static void main(String[] args) {Scanner sc = new Scanner(System.in);int n;while (true){System.out.println("enter a number");n = sc.nextInt();if ( n>0 && n<9999999 ){break;}elseSystem.out.println("输入错误");}String str="";do {int g = n % 10;n = n / 10;str = daxie(g).concat(str);//变成大写} while (n != 0);int len = str.length();for (int i = 0; i < (7-len); i++) {//把前置零加上String s = "零";str = s.concat(str);}
//方法一
//        char []arr = str.toCharArray();//变成字符数组
//        String last = "";
//        last +=arr[0]+"百";
//        last+=arr[1]+"拾";
//        last+=arr[2]+"万";
//        last+=arr[3]+"千";
//        last+=arr[4]+"百";
//        last+=arr[5]+"拾";
//        last+=arr[6]+"元";
//        System.out.println(last);//方法二String []arrs = {"百","拾","万","千","百","拾","元"};for (int i = 0; i < str.length(); i++) {char ch = str.charAt(i);System.out.print(ch);System.out.print(arrs[i]);}}private static String daxie(int n){String []arr = {"零","壹","贰","叁","肆","伍","陆","柒","捌","玖"};return arr[n];}
}

8 手机号屏蔽

import java.util.Scanner;public class abc {public static void main(String[] args) {Scanner sc = new Scanner(System.in);String str = sc.nextLine();String str1 = str.substring(0, 3);String str2 = str.substring(str.length()-4);System.out.println(str1+"****"+str2);}
}

9 罗马数字转换

 代码实现

import java.util.Scanner;public class abc {public static void main(String[] args) {System.out.println("输入一个数字");Scanner sc = new Scanner(System.in);String str;while (true) {str = sc.next();boolean flag = Isintnum(str);if (flag) {break;}elseSystem.out.println("请重新输入");}StringBuilder p = new StringBuilder();for (char c : str.toCharArray()) {int i = c - '0';p.append(Luoma(i));}System.out.println(p);}private static String Luoma(int num){String [] arr =  {"","I ","II ","III ","IV ","V ","VI ","VII ","VIII ","IX "};return arr[num];}private static boolean Isintnum(String str){for (int i = 0; i < str.length(); i++) {if (str.charAt(i) < '0' || str.charAt(i) > '9') {return false;}}return true;}
}

10 调整字符串

代码实现

import java.util.Scanner;public class abc {public static void main(String[] args) {Scanner sc = new Scanner(System.in);String next = sc.next();String next2 = sc.next();boolean flag = false;for (int i = 0; i < next.length(); i++) {next = xuanzhuan(next);if (next2.equals(next)) {System.out.println("YES");flag = true;}}if (!flag) {System.out.println("NO");}}private static String xuanzhuan(String next){String s;s = next.charAt(0)+"";next = next.substring(1);next = next+s;return next;}
}

11 初级学生管理系统

创建一个学生类

public class Student {private String id;private String name;private int age;private String address;public Student() {}public Student(String id, String name, int age,String address) {this.id = id;this.name = name;this.age = age;}public String getId() {return id;}public void setId(String id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}
}

相关方法的实现

import java.util.ArrayList;
import java.util.Scanner;public class StudentManage {public static void main(String[] args) {ArrayList<Student> students = new ArrayList<>();loop:while (true) {System.out.println("    ==欢迎来到学生管理系统==");System.out.println(" 输入 1 - 添加学生信息");System.out.println(" 输入 2 - 删除学生信息");System.out.println(" 输入 3 - 更改学生信息");System.out.println(" 输入 4 - 查询学生信息");System.out.println(" 输入 5 - 退出系统");System.out.println(" ");System.out.print("输入你的需求： ");Scanner sc = new Scanner(System.in);int choice = sc.nextInt();switch (choice) {case 1: addstudent(students);break;case 2: delstudent(students);break;case 3: changestudent(students);break;case 4: squrestudent(students);break;case 5: {System.out.println("已退出学生管理系统");break loop;} default:System.out.println("没有这个选项，请重新输入：");}}}private static void squrestudent(ArrayList<Student> students) {//查询遍历，（空学生表的判断）if (students.isEmpty()) {System.out.println("请添加后再查询");}else{System.out.println("id       姓名 年龄 住址");for (Student student : students) {System.out.println(student.getId() + " " + student.getName()+ " " + student.getAge() + " " + student.getAddress());}}}private static void changestudent(ArrayList<Student> students) {//更改学生表的成员，根据id信息更改if (students.isEmpty()) {System.out.println("请添加后再更改");}else{Scanner sc = new Scanner(System.in);System.out.println("输入id");String id = sc.next();if(!idtest(students, id)){System.out.println("id 匹配成功");System.out.println("输入姓名");String name = sc.next();System.out.println("输入年龄");int age = sc.nextInt();System.out.println("输入地址");String address = sc.next();for (Student student : students) {if (student.getId().equals(id)) {student.setId(id);student.setName(name);student.setAge(age);student.setAddress(address);System.out.println("更改成功");}}}elseSystem.out.println("无这个 id 信息，请重新选择你的需求");}}private static void delstudent(ArrayList<Student> students) {//删除学生表成员信息，要判断是否存在System.out.println("请输入id信息");Scanner sc = new Scanner(System.in);String id = sc.next();for (int i = 0; i < students.size(); i++) {if (students.get(i).getId().equals(id)) {students.remove(i);System.out.println("删除成功");break;}if ( i == students.size() - 1) {System.out.println("无这个学生信息，请添加之后再进行操作");}}}private static void addstudent(ArrayList<Student> students) {//添加学生表成员信息//        System.out.println("分别输入  id  姓名  年龄  住址");
//        Scanner sc = new Scanner(System.in);
//        Student student = new Student(sc.next(),sc.next(),sc.nextInt(),sc.next());//添加方法一
//        students.add(student);Student student = new Student();Scanner sc = new Scanner(System.in);//添加方法二System.out.println("输入id");while(true){String id = sc.next();if (idtest(students,id)) {student.setId(id);break;}elseSystem.out.println("id已经存在 请重新输入");}System.out.println("输入姓名");String name = sc.next();student.setName(name);System.out.println("输入年龄");int age = sc.nextInt();student.setAge(age);System.out.println("输入住址");String address = sc.next();student.setAddress(address);students.add(student);System.out.println("学生信息添加成功");}private static boolean idtest(ArrayList<Student> students,String id) { // 不存在返回truefor (Student student : students) {if (student.getId().equals(id)) {return false;}}return true;}
}

12 学生管理系统（升级版）

三种需求

用户账号注册

用户账号登陆

用户忘记密码

代码实现