第七周上机练习

1.有10个评委打分,(去掉一个最高一个最低)求平均分。

package pra;

import java.util.Scanner;

public class Text1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double sum = 0;
        Scanner input = new Scanner(System.in);
        System.out.println("请输入评委个数：");
        int n = input.nextInt();
        int[] score = new int[n];
        for (int i = 0; i < n; i++) {
            System.out.println("请输入第" + (i + 1) + "个评委的分数：");
            score[i] = input.nextInt();
        }
        for (int i = 0; i < score.length - 1; i++) {
            for (int j = 0; j < score.length - 1 - i; j++) {
                if (score[j] > score[j + 1]) {
                    int temp = score[j];
                    score[j] = score[j + 1];
                    score[j + 1] = temp;
                }
            }
        }
        for (int i = 1; i < score.length - 1; i++) {
            sum += score[i];
        }
        double aver = (sum / (score.length - 2)); 
        System.out.println("平均分为：" + aver);

    }

}

 

 

 2.自学一下Java随机数，生成一个长度为10的随机数组（每个数的范围是0~99），排序后输出。

package pra;

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

public class Text1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int arr[] = new int[10];
        Random r = new Random();
        for (int i = 0; i < arr.length; i++) {
            arr[i] = r.nextInt(100);
        }
        for (int i = 0; i < arr.length - 1; i++) {
            for (int n = 0; n < arr.length - 1 - i; n++) {
                if (arr[n] > arr[n + 1]) {
                    int c = arr[n];
                    arr[n] = arr[n + 1];
                    arr[n + 1] = c;
                }
            }

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

    }

}

 

 

3.制作彩票35选7程序。 （就是1~35随机生成7个不重复的数）

 

 

package pra;

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

public class Text1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Object[] values = new Object[7];

        Random random = new Random();
        HashMap<Object, Object> hashMap = new HashMap<Object, Object>();

        /******* 生成随机数字并存入 HashMap *******/
        for (int i = 0; i < values.length; i++) {
            int number = random.nextInt(35) + 1;
            hashMap.put(number, i);
        }

        /********** 从 HashMap 导入数组 **********/
        values = hashMap.keySet().toArray();

        /*********** 遍历数组并打印数据 ***********/
        for (int i = 0; i < values.length; i++) {
            System.out.print(values[i] + " ");
            if ((i + 1) % 10 == 0) {
                System.out.println(" ");
            }
        }

    }

}

 

4.定义一个长度为10的int数组(如果没有特殊说明,静态赋值动态赋值都可以),统计数组中的最大值、最小值、以及奇数和偶数的个数

 

package pra;

import java.util.Scanner;

public class Text1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int max = 0, min = 99;
        int os = 0, js = 0;
        int[] a = { 12, 15, 88, 77, 45, 63, 25, 88, 45, 16 };
        for (int i = 0; i < a.length; i++) {
            if (a[i] < min) {
                min = a[i];
            }
            if (a[i] > max) {
                max = a[i];
            }
        }
        for (int i = 0; i < a.length; i++) {
            if (a[i] % 2 == 0) {
                os++;
            } else {
                js++;
            }
        }
        System.out.println("偶数出现的次数:" + os);
        System.out.println("奇数出现的次数:" + js);
        System.out.println("最大值:" + max);
        System.out.println("最小值:" + min);
    }

}