JAVA学习第五章——专题训练

卖飞机票

机票价格按照，淡季和旺季、头等舱和经济舱收费。输入机票原价、月价和头等舱或经济舱

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

package math.math;

import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入票价：");
        double ticket = sc.nextInt();
        System.out.println("请输入月份：");
        int moon = sc.nextInt();
        System.out.println("请输入仓位：1为头等舱 0为经济舱");
        int dinner = sc.nextInt();

        if (moon >= 5 && moon <= 10) {

            if (dinner == 1) {
                ticket = ticket * 0.9;

            } else if (dinner == 0) {
                ticket = ticket * 0.85;

            } else {
                System.out.println("输入不合法");
            }

        } else if ((moon >= 1 && moon <= 4) || (moon >= 11 && moon <= 12)) {

            if (dinner == 1) {
                ticket = ticket * 0.7;

            } else if (dinner == 0) {
                ticket = ticket * 0.65;

            } else {
                System.out.println("输入不合法");
            }

        } else {
            System.out.println("录入月份不合法");
        }

        System.out.println(ticket);
    }

}

---

找质数

判断101~202之间有多少个质数，并输出所以质数

package math.math;

public class test {
    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 + " ");

                count++;

            }
        }

        System.out.println(count);

    }
}

---

开发验证码

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

package math.math;

import java.util.Random;

public class test {
    public static void main(String[] args) {
        char[] chs = new  char[52];
        for (int i = 0; i < chs.length; i++) {

            if(i <= 25){
                chs[i] = (char)(97 + i) ;
            }else {
                chs[i] = (char)(65 + i - 26);
            }

        }

        String result = "";

        Random r = new Random() ;

        for (int i = 0; i < 4; i++) {
            int random =  r.nextInt(chs.length);
            result = result + chs[random] ;
        }

        int number = r.nextInt(10);

        result= result + number ;

        System.out.println(result);
    }
}

---

数组元素的复制

把一个数组中的元素复制到另一个新数组中去

package math.math;

public class newclass {
    public static void main(String[] args) {
        int[] ne = {1,3,5,7,8,10} ;
        int[] me = new int[ne.length];
        for (int i = 0; i < ne.length; i++) {
            me[i] = ne[i] ;
        }

        for (int i = 0; i < me.length; i++) {
            System.out.println(me[i]);
        }
        
    }
}

评委打分

在歌唱比赛中，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。

package math.math;

import java.util.Scanner;

public class newclass {
    public static void main(String[] args) {
        int[] scoreA = get();
        int max = max(scoreA);
        int min = min(scoreA);
        int sum = sum(scoreA);

        int get = (sum - max - min) / (scoreA.length - 2);

        System.out.println("平均分为：" + get);

    }

    //成绩录入数组
    public static int[] get() {
        int[] arr = new int[6];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 6; ) {
            System.out.println("请输入评委的打分");
            int score = sc.nextInt();
            if (score >= 0 && score <= 100) {
                arr[i] = score;
                i++;
            } else {
                System.out.println("成绩无效，重新输入");
            }
        }

        return arr;
    }

    //求录入数组最大值
    public static int max(int[] arr) {
        int max = arr[0];
        for (int i = 1; i < arr.length; i++) {
            if (arr[i] > max) {
                max = arr[i];
            }
        }
        return max;
    }

    //求录入数组最小值
    public static int min(int[] arr) {
        int min = arr[0];
        for (int i = 1; i < arr.length; i++) {
            if (arr[i] < min) {
                min = arr[i];
            }
        }
        return min;
    }

    //求和
    public static int sum(int[] arr) {
        int sum = 0;
        for (int i = 0; i < arr.length; i++) {
            sum = sum + arr[i];
        }
        return sum;
    }

}

数字加密

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：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

package math.math;

import java.util.Scanner;

public class newtest {
    public static void main(String[] args) {


        Scanner sc = new Scanner(System.in);
        System.out.println("输入密码：");
        int number = sc.nextInt();
        int temp = number;

        //确定数组长度
        int count = 0;
        while (number != 0) {
            number = number / 10;
            count++;
        }
        int[] ra = new int[count];

        //输入值添加入数组
        int index = ra.length - 1;
        while (temp != 0) {
            int ge = temp % 10;
            temp = temp / 10;
            ra[index] = ge;
            index--;
        }
        
        //加法
        for (int i = 0; i < ra.length; i++) {
            ra[i] = ra[i] + 5;
        }

        //取余
        for (int i = 0; i < ra.length; i++) {
            ra[i] = ra[i] % 10;
        }

        //调换
        for (int i = 0, j = ra.length - 1; i < j; i++, j--) {
            int tem = ra[i];
            ra[i] = ra[j];
            ra[j] = tem;
        }

        //求和
        int numbe = 0;
        for (int i = 0; i < ra.length; i++) {
            numbe = numbe * 10 + ra[i];
        }

        System.out.println(numbe);


    }
}

抢红包

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。

package math.math;

import java.util.Random;

public class threeTest {
    public static void main(String[] args) {
        int[] arr = {2, 588, 888, 1000, 10000};
        int[] newarr = new int[arr.length];
        Random r = new Random();

        for (int i = 0; i < 5; ) {
            int rand = r.nextInt(arr.length);

            int prize = arr[rand];

            boolean flag = contains(newarr, prize);
            if (!flag) {
                newarr[i] = prize;
                i++;
            }
        }

        for (int i = 0; i < newarr.length; i++) {
            System.out.println(newarr[i] + "已经被抽出");
        }
    }

    public static boolean contains(int[] arr, int prize) {
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] == prize) {
                return true;
            }
        }
        return false;
    }
}

双色球系统

package math.math;

import java.util.Random;
import java.util.Scanner;

public class fourTest {
    public static void main(String[] args) {
        int[] arr = CNumber();

        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }

        int[] userinput = user();
        for (int i = 0; i < userinput.length; i++) {
            System.out.print(userinput[i] + " ");
        }

        int redCount = 0;
        int blueCount = 0;
        for (int i = 0; i < userinput.length - 1; i++) {
            int redNumber = userinput[i] ;
            for (int j = 0; j < arr.length - 1; j++) {
                if(redNumber == arr[j]){
                    redCount++ ;
                    break;
                }
            }
        }
        int blueNumber = userinput[userinput.length - 1];
        if (blueNumber == arr[arr.length - 1]){
            blueCount++;
        }

        if(redCount == 6 && blueCount == 1){
            System.out.println("头奖");
        }else if (redCount == 6 && blueCount == 0){
            System.out.println("次奖");
        }else {
            System.out.println("低等奖");
        }

    }

    public static int[] user() {
        int[] arr = new int[7];
        Scanner sc = new Scanner(System.in);
        //红球号码输入
        for (int i = 0; i < 6; ) {
            System.out.println("请输入红球号码：");
            int redNumber = sc.nextInt();
            if (redNumber >= 1 && redNumber <= 33) {
                boolean flag = contains(arr, redNumber);

                if (!flag) {
                    //不存在，可以添加
                    arr[i] = redNumber;
                    i++;
                } else {
                    System.out.println("号码重复");
                }


            } else {
                System.out.println("输入号码不合规");
            }
        }
        //篮球号码输入
        while (true) {
            System.out.println("请输入篮球号码：");
            int blueNumber = sc.nextInt();
            if (blueNumber >= 1 && blueNumber <= 16){

                arr[arr.length - 1] = blueNumber ;
                break;
            }else {
                System.out.println("输入号码不合规");
            }
        }
        return arr ;
    }

    public static int[] CNumber() {
        int[] arr = new int[7];
        Random r = new Random();
        for (int i = 0; i < 6; ) {
            int redNumber = r.nextInt(33) + 1;
            boolean flag = contains(arr, redNumber);
            if (!flag) {
                arr[i] = redNumber;
                i++;
            }
        }

        int blueNumber = r.nextInt(16) + 1;
        arr[arr.length - 1] = blueNumber;
        return arr;
    }

    public static boolean contains(int[] arr, int number) {
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] == number) {
                return true;
            }
        }
        return false;
    }
}

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