元旦作业 1~6题

package cn.yang.qian.qian;

import java.util.Scanner;

public class average1 {
	public static void main(String[] args) {
		// 第一题 计算平均分
		Scanner input = new Scanner(System.in);
		System.out.println("请输入语文成绩");
		double Chinese = input.nextDouble();
		System.out.println("请输入数学成绩");
		double Math = input.nextDouble();
		System.out.println("请输入英语成绩");
		double English = input.nextDouble();

		double sum = Chinese + Math + English;
		double average = sum / 3;
		System.out.println("总成绩是:" + sum);
		System.out.println("平均分是:" + average);
	}
}

package cn.yang.qian.qian;

public class shopping2 {
	public static void main(String[] args) {
		// 第二题 购物清单
		int bagPrice = 198;
		int badmintonPrice = 90;
		int battledorePrice = 400;
		System.out.println("********** 购 物 清 单 **********");
		System.out.println("商品名称" + "\t" + "单价" + "\t" + "数量" + "\t" + "总价");
		System.out.println("登山包" + "\t" + "￥" + bagPrice + "\t" + "1" + "\t"
				+ "￥" + bagPrice * 1);
		System.out.println("羽毛球" + "\t" + "￥" + badmintonPrice + "\t" + "3"
				+ "\t" + "￥" + badmintonPrice * 3);
		System.out.println("羽毛球拍" + "\t" + "￥" + battledorePrice + "\t" + "1"
				+ "\t" + "￥" + battledorePrice * 1);
		System.out.println("==============================");
		int sum = bagPrice * 1 + badmintonPrice * 3 + battledorePrice * 1;
		int money = 8888;
		int change = money - sum;
		System.out.println("应付金额:" + sum + "元");
		System.out.println("实收金额:" + money + "元");
		System.out.println("找零:" + change + "元");

	}
}


package cn.yang.qian.qian;

import java.util.Scanner;

public class performance3 {
	public static void main(String[] args) {
		// 第三题 接收成绩 分等级
		double student[] = new double[10];
		double sum = 0;// 总成绩
		double score = 0;// 平均分
		Scanner input = new Scanner(System.in);
		for (int i = 0; i < student.length; i++) {
			System.out.println("请输入第" + (i + 1) + "名学生的成绩");
			student[i] = input.nextDouble();
			if (student[i] > 100 || student[i] < 1) {
				System.out.println("输入成绩无效");
				break;
			}
			sum = sum + student[i];
			score = sum / 10;
		}
		if (score >= 1) {
			int a = (int) score / 10;
			switch (a) {
			case 10:
			case 9:
				System.out.println("该班级学员等级为A");
				break;
			case 8:
				System.out.println("该班级学员等级为B");
				break;
			case 7:
				System.out.println("该班级学员等级为C");
				break;
			case 6:
				System.out.println("该班级学员等级为D");
				break;
			case 5:
			case 4:
			case 3:
			case 2:
			case 1:
			case 0:
				System.out.println("该班级学员等级为E");
				break;
			}
		}
	}
}


package cn.yang.qian.qian;

public class test4 {
	public static void main(String[] args) {
		// 第四题 输出1~1000之间5的倍数 并统计个数
		int conut = 0;
		System.out.println("1~1000之间5的倍数为:");
		for (int i = 1; i <= 1000; i++) {
			if (i % 5 != 0) {
				continue;
			} else {
				conut++;
				if (conut % 8 == 0) {
					System.out.println(i);
				} else {
					System.out.print(i + "\t");
				}

			}
		}
		System.out.println("1~1000之间5个倍数一共有" + conut + "个");
	}
}


package cn.yang.qian.qian;

import java.util.Arrays;
import java.util.Scanner;

public class test5 {
	public static void main(String[] args) {
		// 第五题 录入成绩 按降序排列
		int student[] = new int[10];
		int a = 0;
		int b = 0;
		int c = 0;
		Scanner input = new Scanner(System.in);
		System.out.println("学员成绩统计表");
		for (int i = 0; i < student.length; i++) {
			System.out.println("请输入第" + (i + 1) + "个学员的成绩");
			student[i] = input.nextInt();
		}
		System.out.println("********************************");
		System.out.println("降序输出所有成绩为:");
		Arrays.sort(student);// 排序
		for (int i = student.length - 1; i >= 0; i--) {
			System.out.print(student[i] + " ");
			if (student[i] >= 80 && student[i] <= 100) {
				a++;
			}
			if (student[i] >= 60 && student[i] < 80) {
				b++;
			}
			if (student[i] < 60) {
				c++;
			}
		}
		System.out.println("\t");
		System.out.println("********************************");
		System.out.println("其中:");
		System.out.println("100分--80分的学员有:" + a + "个");
		System.out.println("79分--60分的学员有:" + b + "个");
		System.out.println("60分以下的学员有:" + c + "个");
	}
}


package cn.yang.qian.qian;

import java.util.Arrays;
import java.util.Scanner;

public class test6 {
	public static void main(String[] args) {
		// 输入数据 判断是否存在数组中
		int qianqian[] = new int[5];
		Scanner input = new Scanner(System.in);
		for (int i = 0; i < qianqian.length; i++) {
			System.out.println("请输入第" + (i + 1) + "个数字");
			qianqian[i] = input.nextInt();
		}
		System.out.print("所接受的数字为:[");
		for (int qian : qianqian) {
			System.out.print(qian + ",");
		}
		System.out.println("]");
		System.out.println("请输入查询数字");
		int number = input.nextInt();
		int count = Arrays.binarySearch(qianqian, number);
		if (count == -1) {
			System.out.println("该数字不存在与本数组中");
		} else {
			System.out.println("该数字是本数组中第:" + (count + 1) + "个成员");
		}
		String str = Arrays.toString(Arrays.copyOf(qianqian, number));
		if (count == 0) {
			System.out.println("该数字前无数据");
		} else {
			System.out.println("该数字前的数组内容为:" + str);
		}
	}
}