1.
public class lcx {
public static void mp() {
Scanner input = new Scanner(System.in);
int a[] = new int[5];
System.out.println("请输入5个数:");
for (int i = 0; i < a.length; i++) {
a[i] = input.nextInt();
}
for (int i = 0; i < a.length - 1; i++) {
for (int j = 0; j < a.length - 1 - i; j++) {
if (a[j] > a[j + 1]) {
int temp = a[j];
a[j] = a[j + 1];
a[j + 1] = temp;
}
}
}
System.out.println("排序后的顺序为:");
for (int i = 0; i < a.length; i++) {
System.out.println(a[i]);
}
}
public static void main(String[] args) {
mp();
}
}
2
public class lcx {
public static int jc(int b) {
int sum=1;
for(int a=1;a<=b;a++){
sum*=a;
}
return sum;
}
public static void main(String[] args){
System.out.println(jc(5));
}
}
3
public class lcx {
public static void mld() {
Scanner input=new Scanner(System.in);
System.out.println("请输入年份");
int year=input.nextInt();
if(year % 4== 0 && year % 100 != 0 || year % 400 == 0 ){
System.out.println("该年为闰年");
}else{
System.out.println("该年为平年");
}
}
public static void main(String[] args){
mld();
}
}
4
public class lcx {
public static void mainMenu() {
Scanner input =new Scanner(System.in);
System.out.println("欢迎使用本系统");
System.out.println("1.登录");
System.out.println("2.注册");
System.out.println("3.幸运抽奖");
System.out.println("4.退出");
System.out.println("请选择");
int a=input.nextInt();
switch(a){
case 1:
login();
break;
case 2:
reg();
break;
case 3:
lucky();
}
}
public static void lucky(){
//输入四位会员卡号，如果百位数等于随机数，幸运会员。否则不是。同时也要询问是否返回主菜单
Scanner input=new Scanner(System.in);
System.out.println("输入一个四位数");
Random r=new Random();
int x=r.nextInt(10);
int num =input.nextInt();
while (num<100||num>10000){
System.out.println("输入有误，重新输入");
num=input.nextInt();
if(num >= 1000 && num < 10000){
break;
}
}
int bai =num%1000/100;
if(bai==x){
System.out.println("幸运会员");
}else{
System.out.println("不是幸运会员");
}
returnMain();
}
public static void returnMain(){
Scanner input=new Scanner(System.in);
System.out.println("是否返回主菜单？");
if(input.next().equalsIgnoreCase("Y"))
mainMenu();
else
System.out.println("谢谢使用");
}
public static void reg(){
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
System.out.println("输入要注册的用户名");
String uname = input.next();
System.out.println("输入注册密码");
String upwd = input.next();
System.out.println("注册成功");
returnMain();
}
public static void login(){
Scanner input = new Scanner(System.in);
System.out.println("输入用户名");
String uname = input.next();
System.out.println("输入密码");
String upwd = input.next();
if(uname.equals("zs")&& upwd.equals("123")){
System.out.println("ok");
}else{
System.out.println("fail");
}
returnMain();
}
public static void main(String[] args){
mainMenu();
}
}
