caseExercise
随机验证码
package com.fan.caseExercise;
import java.util.Random;
public class Demo01 {
public static void main(String[] args) {
String code = createCode(5); //输入你想要的验证码位数
System.out.println(code);
}
public static String createCode(int n){
//1.定义一个for循环，用于控制产生多少位随机字符
Random random = new Random();
//3.定义一个String类型的变量，用于记忆产生的每位随机字符
String code = "";
for (int i = 1; i <= n; i++) {
//2.为每一个位置生成一个随机字符
int r = random.nextInt(3); //随机一个 0 1 2 ，0代表随机数字；1 2代表随机大小写字母
switch (r){
case 0:
//随即一个数字
code += random.nextInt(10);
break;
case 1:
//随机一个大写字母 A 65 Z 65+25 （0-25）+ 65
char ch1 = (char) (random.nextInt(26) + 65);
code += ch1;
break;
case 2:
//随机一个小写字母 a 97 z 97+25
char ch2 = (char) (random.nextInt(26) + 97);
code += ch2;
break;
}
}
return code;
}
}
评委打分
package com.fan.caseExercise;
import java.util.Scanner;
public class Democracy {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入评委的人数：");
int count = scanner.nextInt();
//引用方法 （直接输出引用）
System.out.println(arvergeScore(count));
}
public static double arvergeScore (int num) {
//接收评委打分
int[] score = new int[num];
for (int i = 0; i < score.length; i++) {
System.out.println("请输入第" + (i+1) + "个评委的打分：");
Scanner scanner1 = new Scanner(System.in);
int score1 = scanner1.nextInt();
score[i] = score1;
}
//冒泡排序 （升序）
int x =0;
for (int i = 0; i < score.length; i++) {
for (int j = 0; j < score.length - 1; j++) {
if (score[j] > score[j+1]){
x = score[j];
score[j] = score[j+1];
score[j+1] = x;
}
}
}
//舍去极端值，求平均数
double sum = 0;
for (int i = 0; i < score.length - 1; i++) {
if (i != 0){
sum += score[i];
}
}
//返回结果
//return sum;
return 1.0 * (sum / (score.length - 2));
}
}
数字加密
package com.fan.caseExercise;
import java.util.Scanner;
public class Demo03 {
public static void main(String[] args) {
int[] code = new int[4];
System.out.println("请依次输入您的四位数密码：");
//对Scanner使用for循环捕捉键盘上的数据并依次交给code数组
for (int i = 0; i <= 3; i++) {
Scanner scanneri = new Scanner(System.in);
code[i] = scanneri.nextInt();
}
//遍历加密后的数组
for (int i:enc(code)){
System.out.print(i + "\t");
}
}
public static int[] enc (int[] array) {
int[] x = new int[array.length];//承接加密后的密码
int j = array.length-1;
//加密
for (int i = 0; i < array.length; i++) {
if (j>=0){
x[j] = (array[i] + 5) % 10; //对code数组中的每个数字进行+5 再对10求余 最后反转
j--;
}
}
//返回加密后的密码x
System.out.println("-------------");
return x;
}
}
精简优化版
package com.fan.caseExercise;
import java.util.Scanner;
public class Demo03 {
public static void main(String[] args) {
int[] code = new int[4];
System.out.println("请依次输入您的四位数密码：");
//对Scanner使用for循环捕捉键盘上的数据并依次交给code数组
for (int i = 0; i <= 3; i++) {
Scanner scanneri = new Scanner(System.in);
code[i] = scanneri.nextInt();
}
//遍历加密后的数组
for (int i:enc(code)){
System.out.print(i + "\t");
}
}
public static int[] enc (int[] array) {
int[] x = new int[array.length];//承接加密后的密码
//加密
for (int i = 0, j = array.length-1; i < array.length && j>=0; i++,j--) {
x[j] = (array[i] + 5) % 10; //对code数组中的每个数字进行+5 再对10求余 最后反转
}
//返回加密后的密码x
System.out.println("-------------");
return x;
}
}
抽红包
1.0版本（多损耗性能）
package com.fan.caseExercise;
import java.util.Random;
import java.util.Scanner;
public class Demo04 {
public static void main(String[] args) {
//设立奖池
int[] moneys = {9,666,188,520,99999};
//调用抽奖方法
draw(moneys);
}
public static void draw (int[] arr){
Scanner sc = new Scanner(System.in);
System.out.println("请输入任意符号开始抽奖！");
//抽5次奖
for (int i = 1; i <= 5; i++) {
sc.next(); //Enter进行下一步操作 模拟抽奖开始按钮
while (true) {
Random r = new Random();
int index = r.nextInt(arr.length);
if (arr[index] != 0) { //若等于0表示轮空，系统内部重新抽奖
System.out.println("您的中奖金额为：" + arr[index]);
arr[index] = 0; //刷新奖池
break; //结束本次抽奖
}
}
}
System.out.print("--------------" + "\n" + "奖池已瓜分完毕！");
}
}
2.0版本（利用换牌算法实现）
package com.fan.caseExercise;
import java.util.Random;
import java.util.Scanner;
public class Demo05 {
public static void main(String[] args) {
//设立奖池
int[] moneys = {9,666,188,520,99999};
//调用抽奖方法
draw(moneys);
}
public static void draw (int[] arr){
//洗牌算法（换牌算法）
//每次让数组中第 n=arr.length-1 (n--)元素与任意一个元素互换
//（包括自己与自己互换）(互换后锁定最后一个元素)
for (int i = arr.length-1; i > 0; i--) { //选取数组中最后一个元素
Random r = new Random();
int j = r.nextInt(i+1); //从下标（0~i）中随机选取一个元素
//arr[i]与arr[j]互换
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
Scanner sc = new Scanner(System.in);
System.out.println("请输入任意字符并按下Enter键开始抽奖！");
for (int i = 0; i < arr.length; i++) {
sc.next(); //模拟用户开始抽奖交互按钮
System.out.print("您的中奖金额为：" + arr[i] + "\n-----------------\n");
}
System.out.println("奖池已瓜分完毕！");
}
}
找质数
package com.fan.caseExercise;
public class Demo06 {
public static void main(String[] args) {
System.out.println(prim(101,200));
}
public static int prim (int start,int end){
int count = 0;
OUT:
for (int i = start; i <= end ; i++) {
for (int j = 2; j <= Math.sqrt(i); j++) {
if (i % j == 0){
continue OUT;
}
}
System.out.println(i);
count++;
}
System.out.println("质数的个数为：");
return count;
}
}
双色球
package com.fan.caseExercise;
import java.util.Random;
import java.util.Scanner;
public class Demo07 {
public static void main(String[] args) {
int[] user = DCB();
int[] lucy = creatLucyNumbers();
System.out.print("您的号码为：\t");
PrintArray(user);
System.out.print("中奖号码为：\t");
PrintArray(lucy);
System.out.print("中奖情况为：\t");
judge(user,lucy);
}
//打印数组
public static void PrintArray(int[] arr) {
System.out.print("[");
for (int i = 0; i < 7; i++) {
System.out.print(i == 6 ? arr[i] : arr[i] + ",");
}
System.out.println("]");
}
//读取用户输入的双色球号码
public static int[] DCB (){
int[] dbc= new int[7];
Scanner sc = new Scanner(System.in);
Scanner sc1 = new Scanner(System.in);
//红球
for (int i = 0; i < 6; i++) {
while (true) {
System.out.println("请输入第"+(i+1)+"个红球号码（1~33）：");
int num = sc.nextInt();
if (num < 1 || num > 33) {
System.out.println("号码超出范围，请重新输入！");
}else {
if (chRe(dbc,num)){
dbc[i] = num;
break;
}else {
System.out.println("号码重复，请重新输入！");
}
}
}
}
//蓝球
while (true) {
System.out.println("请输入蓝球号码（1~16）：");
int num = sc1.nextInt();
if (num < 1 || num > 16) {
System.out.println("号码超出范围，请重新输入！");
} else {
dbc[6] = num;
break;
}
}
return dbc;
}
//检查号码是否重复(T代表不重复)
public static boolean chRe (int[] arr,int number){
boolean x = true;
for (int i = 0; i < 6; i++) {
if (arr[i] == 0){
return x;
}
if (arr[i] == number){
x = false;
return x;
}
}
return x;
}
//生成随机中奖号码
public static int[] creatLucyNumbers(){
Random r = new Random();
int[] Lucys= new int[7];
//随机红球号码
for (int i = 0; i < Lucys.length - 1; i++) {
while (true) {
int LucyNumber = r.nextInt(33) + 1;
if (chRe(Lucys, LucyNumber)) {
Lucys[i] = LucyNumber;
break;
}
}
}
//随机蓝球号码
Lucys[6] = r.nextInt(16) + 1;;
return Lucys;
}
//检查中奖情况
public static void judge(int[] userNUmbers,int[] lucyNumbers){
int redcount = 0;
int bluecount = 0;
//判断红球中奖数量
for (int i = 0; i < userNUmbers.length - 1; i++) {
for (int j = 0; j < lucyNumbers.length - 1; j++) {
if (userNUmbers[i] == lucyNumbers[j]){
redcount++;
break;
}
}
}
//判断蓝球是否命中
bluecount = userNUmbers[6] == lucyNumbers[6] ? 1 : 0;
//判断中奖情况
if (bluecount == 1){
switch (redcount){
case (6):
System.out.println("恭喜中奖，金额为：10000000元！");
break;
case (5):
System.out.println("恭喜中奖，金额为：3000元！");
break;
case (4):
System.out.println("恭喜中奖，金额为：200元！");
break;
case (3):
System.out.println("恭喜中奖，金额为：10元！");
break;
case (2):
case (1):
case (0):
System.out.println("恭喜中奖，金额为：5元！");
break;
}
}else {
switch (redcount){
case (6):
System.out.println("恭喜中奖，金额为：5000000元！");
break;
case (5):
System.out.println("恭喜中奖，金额为：200元！");
break;
case (4):
System.out.println("恭喜中奖，金额为：10元！");
break;
case (3):
case (2):
case (1):
case (0):
System.out.println("没中~~~");
}
}
}
}
PS：这么难中的吗？
浙公网安备 33010602011771号