11201771010119穷吉
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理论知识:
一般将数据结构分为两大类:线性数据结构和非线性数据结构
线性数据结构:线性表、栈、队列、串、数组和文件
非线性数据结构:树和图。
线性表:1.所有数据元素在同一个线性表中必须是相同的数据类型。
2. 线性表按其存储结构可分为顺序表和链表
3. 用顺序存储结构存储的线性表称为顺序表
4. 顺序表将线性表中的数据元素依次存放在某个存储区域中。一维数组就是用顺序方式存储的线性表。
5. 用链式存储结构存储的线性表称为链表
栈:1. 栈(Stack)也是一种特殊的线性表,是一种后进先出的结构
2. 栈是限定仅在表尾进行插入和删除运算的线性表,表尾称为栈顶(top),表头称为栈底(bottom)。
3. 栈的物理存储可以用顺序存储结构,也可以用链式存储结构
集合:JAVA的集合框架实现对各种数据结构的封装,以降低对数据管理与处理的难度。
是一种包含多个元素并提供对所包含元素操作方法的类,其包含的元素可以由同一类型的对象组成,也可以由不同类型的对象组成。
集合类的作用:
1. Java的集合类提供了一些基本数据结构的支持。
2.例如Vector、Hashtable、Stack等。
集合类的特点:1. 只容纳对象
2.集合类容纳的对象都是Object类的实例(一旦把一个对象置入集合类中,它的类信息将丢失)
Vector类:类似长度可变的数组,只能存放对象,元素通过下标进行访问。
Stack类:它描述堆栈数据结构。(所有对象都有一个散列码,可以通过Object类的hashCode方法获得。)
实验1: 导入第9章示例程序,测试程序并进行代码注释。
测试程序1:
l 使用JDK命令运行编辑、运行以下三个示例程序,结合运行结果理解程序;
l 掌握Vetor、Stack、Hashtable三个类的用途及常用API。
示例程序1:
import java.util.Vector;//实现自动增长的对象数组 class Cat { private int catNumber; Cat(int i) { catNumber = i; } void print() { System.out.println("Cat #" + catNumber); }
} class Dog { private int dogNumber; Dog(int i) { dogNumber = i; } void print() { System.out.println("Dog #" + dogNumber); } } public class CatsAndDogs { public static void main(String[] args) { Vector cats = new Vector(); for (int i = 0; i < 7; i++) cats.addElement(new Cat(i)); cats.addElement(new Dog(7)); for (int i = 0; i < cats.size(); i++) ((Cat) cats.elementAt(i)).print();//进行强制类型转化 } }
更改后程序如下:
import java.util.Vector;//实现自动增长的对象数组 class Cat { private int catNumber; Cat(int i) { catNumber = i; } void print() { System.out.println("Cat #" + catNumber); } } class Dog { private int dogNumber; Dog(int i) { dogNumber = i; } void print() { System.out.println("Dog #" + dogNumber); } } public class CatsAndDogs { public static void main(String[] args) { Vector cats = new Vector(); for (int i = 0; i < 7; i++) cats.addElement(new Cat(i)); cats.addElement(new Dog(7)); for (int i = 0; i < cats.size(); i++) if (cats.elementAt(i) instanceof Cat) //判断是否能进行强制类型转换 { ((Cat) cats.elementAt(i)).print();//能进行强制类型转换,输出为Cat型 } else { ((Dog) cats.elementAt(i)).print();//不能进行强制类型转化,输出为Dog型 } } }
示例程序2:
import java.util.*; public class Stacks //栈(先进后出) { static String[] months = { "1", "2", "3", "4" }; public static void main(String[] args) { Stack stk = new Stack(); for (int i = 0; i < months.length; i++) stk.push(months[i]);//进栈 System.out.println(stk); System.out.println("element 2=" + stk.elementAt(2)); while (!stk.empty()) System.out.println(stk.pop());//输出出栈元素 } }
示例程序3:
import java.util.*; class Counter { int i = 1;//不加权限修饰符:friendly型 public String toString() //把其他类型的数据转为字符串类型的数据 { return Integer.toString(i); } } public class Statistics { public static void main(String[] args) { Hashtable ht = new Hashtable(); for (int i = 0; i < 10000; i++) { Integer r = new Integer((int) (Math.random() * 20));//生成0到20(不包括20)的整型随机数 if (ht.containsKey(r))//判断r是否是哈希表中一个元素的键值 ((Counter) ht.get(r)).i++;//通过get方法获得其值 else ht.put(r, new Counter());//ht不存在 } System.out.println(ht); } }
测试程序2:
使用JDK命令编辑运行ArrayListDemo和LinkedListDemo两个程序,结合程序运行结果理解程序;
ArrayListDemo:
import java.util.*; public class ArrayListDemo//ArrayList使用了数组的实现 { public static void main(String[] argv) { ArrayList al = new ArrayList(); //在ArrayList中添加大量元素 al.add(new Integer(11)); al.add(new Integer(12)); al.add(new Integer(13)); al.add(new String("hello"));//下标从0开始,添加4个元素 // First print them out using a for loop. System.out.println("Retrieving by index:"); for (int i = 0; i < al.size(); i++) { System.out.println("Element " + i + " = " + al.get(i)); } } }
LinkedListDemo:
程序运行结果如下:
l 在Elipse环境下编辑运行调试教材360页程序9-1,结合程序运行结果理解程序;
l 掌握ArrayList、LinkList两个类的用途及常用API。
程序如下:
import java.util.*; /** * This program demonstrates operations on linked lists. * @version 1.11 2012-01-26 * @author Cay Horstmann */ public class LinkedListTest { public static void main(String[] args) { //创建a和b两个链表 List<String> a = new LinkedList<>();//泛型 a.add("Amy"); a.add("Carl"); a.add("Erica"); List<String> b = new LinkedList<>();//泛型 b.add("Bob"); b.add("Doug"); b.add("Frances"); b.add("Gloria"); //合并a和b中的词 ListIterator<String> aIter = a.listIterator(); Iterator<String> bIter = b.iterator(); while (bIter.hasNext()) { if (aIter.hasNext()) aIter.next(); aIter.add(bIter.next()); } System.out.println(a); //从第二个链表中每隔一个元素删除一个元素 bIter = b.iterator(); while (bIter.hasNext()) { bIter.next(); // skip one element if (bIter.hasNext()) { bIter.next(); // skip next element bIter.remove(); // remove that element } } System.out.println(b); // bulk operation: remove all words in b from a a.removeAll(b); System.out.println(a);//通过AbstractCollection类中的toString方法打印出链表a中的所有元素 } }
测试程序3:
l 运行SetDemo程序,结合运行结果理解程序;
程序如下:
import java.util.*; public class SetDemo { public static void main(String[] argv) { HashSet h = new HashSet(); //也可以 Set h=new HashSet() h.add("One"); h.add("Two"); h.add("One"); // 复制 h.add("Three"); Iterator it = h.iterator(); while (it.hasNext()) { System.out.println(it.next()); } } }
程序运行结果如下:
在Elipse环境下调试教材367页-368程序9-3、9-4,结合程序运行结果理解程序;了解TreeSet类的用途及常用API。
9—3:
import java.util.*; /** * An item with a description and a part number. */ public class Item implements Comparable<Item>//接口(泛型) { private String description; private int partNumber; /** * Constructs an item. * * @param aDescription * the item‘s description * @param aPartNumber * the item‘s part number */ public Item(String aDescription, int aPartNumber)//构造器 { description = aDescription; partNumber = aPartNumber; } /** * Gets the description of this item. * * @return the description */ public String getDescription() { return description; } public String toString() { return "[description=" + description + ", partNumber=" + partNumber + "]"; } public boolean equals(Object otherObject) { if (this == otherObject) return true; if (otherObject == null) return false; if (getClass() != otherObject.getClass()) return false; Item other = (Item) otherObject; return Objects.equals(description, other.description) && partNumber == other.partNumber; } public int hashCode() { return Objects.hash(description, partNumber); } public int compareTo(Item other)//排序 { int diff = Integer.compare(partNumber, other.partNumber); return diff != 0 ? diff : description.compareTo(other.description); } }
9—4:
import java.util.*; /** * This program sorts a set of item by comparing their descriptions. * @version 1.12 2015-06-21 * @author Cay Horstmann */ public class TreeSetTest { public static void main(String[] args) { SortedSet<Item> parts = new TreeSet<>(); parts.add(new Item("Toaster", 1234)); parts.add(new Item("Widget", 4562)); parts.add(new Item("Modem", 9912)); System.out.println(parts); NavigableSet<Item> sortByDescription = new TreeSet<>( Comparator.comparing(Item::getDescription));//把自定义类对象存入TreeSet进行排序 sortByDescription.addAll(parts); System.out.println(sortByDescription); } }
测试程序4:
l 使用JDK命令运行HashMapDemo程序,结合程序运行结果理解程序;
程序如下:
import java.util.*; public class HashMapDemo //基于哈希表的 Map接口的实现,提供所有可选的映射操作 { public static void main(String[] argv) { HashMap h = new HashMap(); // 哈希映射从公司名称到地址 h.put("Adobe", "Mountain View, CA"); h.put("IBM", "White Plains, NY"); h.put("Sun", "Mountain View, CA"); String queryString = "Adobe"; String resultString = (String)h.get(queryString); System.out.println("They are located in: " + resultString); } }
在Elipse环境下调试教材373页程序9-6,结合程序运行结果理解程序;
了解HashMap、TreeMap两个类的用途及常用API。
程序如下:
import java.util.*; /** * This program demonstrates the use of a map with key type String and value type Employee. * @version 1.12 2015-06-21 * @author Cay Horstmann */ public class MapTest//Map在有映射关系时,可以优先考虑 { public static void main(String[] args) { Map<String, Employee> staff = new HashMap<>(); staff.put("144-25-5464", new Employee("Amy Lee")); staff.put("567-24-2546", new Employee("Harry Hacker")); staff.put("157-62-7935", new Employee("Gary Cooper")); staff.put("456-62-5527", new Employee("Francesca Cruz")); // 打印所有条目 System.out.println(staff); // 删除一个条目 staff.remove("567-24-2546"); // 替换一个条目 staff.put("456-62-5527", new Employee("Francesca Miller")); // 查找一个值 System.out.println(staff.get("157-62-7935")); // 遍历所有条目 staff.forEach((k, v) -> System.out.println("key=" + k + ", value=" + v)); } }
程序运行结果如下:
实验2:结对编程练习:
l 关于结对编程:以下图片是一个结对编程场景:两位学习伙伴坐在一起,面对着同一台显示器,使用着同一键盘,同一个鼠标,他们一起思考问题,一起分析问题,一起编写程序。
l 关于结对编程的阐述可参见以下链接:
http://www.cnblogs.com/xinz/archive/2011/08/07/2130332.html
http://en.wikipedia.org/wiki/Pair_programming
l 对于结对编程中代码设计规范的要求参考:
http://www.cnblogs.com/xinz/archive/2011/11/20/2255971.html
以下实验,就让我们来体验一下结对编程的魅力。
l 确定本次实验结对编程合作伙伴:白玛次仁
l 各自运行合作伙伴实验九编程练习1,结合使用体验对所运行程序提出完善建议;
package 异常;
import java.util.Scanner;
public class Demo {
public static void main(String[] args) {
// 用户的答案要从键盘输入,因此需要一个键盘输入流
Scanner in = new Scanner(System.in);
// 定义一个变量用来统计得分
int sum = 0;
for (int i = 0; i < 10; i++) {
// 随机生成两个10以内的随机数作为被除数和除数
int a = (int) Math.round(Math.random() * 100);
int b = (int) Math.round(Math.random() * 100);
System.out.println(a + "/" + b + "=");
// 定义一个整数用来接收用户输入的答案
int c = in.nextInt();
// 判断用户输入的答案是否正确,正确给10分,错误不给分
if (c == a / b) {
sum += 100;
System.out.println("恭喜答案正确");
}
else {
System.out.println("抱歉,答案错误");
}
}
//输出用户的成绩
System.out.println("你的得分为"+sum);
}
}
package shen; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Scanner; public class Main { private static ArrayList<Student> studentlist; public static void main(String[] args) { studentlist = new ArrayList<>(); Scanner scanner = new Scanner(System.in); File file = new File("C:\\Users\\ASUS\\Desktop\\新建文件夹\\身份证号.txt"); try { FileInputStream fis = new FileInputStream(file); BufferedReader in = new BufferedReader(new InputStreamReader(fis)); String temp = null; while ((temp = in.readLine()) != null) { Scanner linescanner = new Scanner(temp); linescanner.useDelimiter(" "); String name = linescanner.next(); String number = linescanner.next(); String sex = linescanner.next(); String age = linescanner.next(); String province = linescanner.nextLine(); Student student = new Student(); student.setName(name); student.setnumber(number); student.setsex(sex); int a = Integer.parseInt(age); student.setage(a); student.setprovince(province); studentlist.add(student); } } catch (FileNotFoundException e) { System.out.println("学生信息文件找不到"); e.printStackTrace(); //加入的捕获异常代码 } catch (IOException e) { System.out.println("学生信息文件读取错误"); e.printStackTrace(); //加入的捕获异常代码 } boolean isTrue = true; while (isTrue) { System.out.println("选择你的操作,输入正确格式的选项"); System.out.println("A.字典排序"); System.out.println("B.输出年龄最大和年龄最小的人"); System.out.println("C.寻找老乡"); System.out.println("D.寻找年龄相近的人"); System.out.println("F.退出"); String m = scanner.next(); switch (m) { case "A": Collections.sort(studentlist); System.out.println(studentlist.toString()); break; case "B": int max = 0, min = 100; int j, k1 = 0, k2 = 0; for (int i = 1; i < studentlist.size(); i++) { j = studentlist.get(i).getage(); if (j > max) { max = j; k1 = i; } if (j < min) { min = j; k2 = i; } } System.out.println("年龄最大:" + studentlist.get(k1)); System.out.println("年龄最小:" + studentlist.get(k2)); break; case "C": System.out.println("老家?"); String find = scanner.next(); String place = find.substring(0, 3); for (int i = 0; i < studentlist.size(); i++) { if (studentlist.get(i).getprovince().substring(1, 4).equals(place)) System.out.println("老乡" + studentlist.get(i)); } break; case "D": System.out.println("年龄:"); int yourage = scanner.nextInt(); int near = agenear(yourage); int value = yourage - studentlist.get(near).getage(); System.out.println("" + studentlist.get(near)); break; case "F": isTrue = false; System.out.println("退出程序!"); break; default: System.out.println("输入有误"); } } } public static int agenear(int age) { int j = 0, min = 53, value = 0, k = 0; for (int i = 0; i < studentlist.size(); i++) { value = studentlist.get(i).getage() - age; if (value < 0) value = -value; if (value < min) { min = value; k = i; } } return k; } } Main
public class Student implements Comparable<Student> { private String name; private String number ; private String sex ; private int age; private String province; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getnumber() { return number; } public void setnumber(String number) { this.number = number; } public String getsex() { return sex ; } public void setsex(String sex ) { this.sex =sex ; } public int getage() { return age; } public void setage(int age) { // int a = Integer.parseInt(age); this.age= age; } public String getprovince() { return province; } public void setprovince(String province) { this.province=province ; } public int compareTo(Student o) { return this.name.compareTo(o.getName()); } public String toString() { return name+" "+sex+" "+age+" "+number+" "+province+" "; } }
各自运行合作伙伴实验十编程练习2,结合使用体验对所运行程序提出完善建议;
package demo; import java.io.FileNotFoundException; import java.io.PrintWriter; import java.util.Random; import java.util.Scanner; public class demo { public static void main(String[] args) { /** *文件输出模块 *1.调用构造函数counter *2.创建文件字符流,将out中的内容设为空(null) *3.将out结果输出到test.txt中 *4.try/catch模块捕获异常 */ Scanner in = new Scanner(System.in); yunsuan counter = new yunsuan(); PrintWriter out = null; try { out = new PrintWriter("test.txt"); } catch (FileNotFoundException e) { System.out.println("文件夹输出失败"); e.printStackTrace(); } /** *四则运算生成模块 *1.定义一个int型sum,计算成绩,并说明生成的运算类型 *2.for语句,将{}内的内容循环10次,从而生成10道题目 *3.随机生成int型a与b,范围在0到100以内;生成int型m,范围为1,2,3,4 *4.利用switch语句,根据生成m的值,随机生成加减乘除四则运算 *5.将循环结果输出到test.txt中 */ int sum = 0; System.out.println("随机生成的四则运算类型"); System.out.println("类型1:除法"); System.out.println("类型2:乘法"); System.out.println("类型3:加法"); System.out.println("类型4:减法"); for (int i = 1; i <= 10; i++) { int a = (int) Math.round(Math.random() * 100); int b = (int) Math.round(Math.random() * 100); int m; Random rand = new Random(); m = (int) rand.nextInt(4) + 1; System.out.println("随机生成的四则运算类型:" + m); switch (m) { case 1: a = b + (int) Math.round(Math.random() * 100); while(b == 0){ b = (int) Math.round(Math.random() * 100); } while(a % b != 0){ a = (int) Math.round(Math.random() * 100); } //若生成的除法式子必须能整除,且满足分母为0的条件,则a一定要大于b,且a模b的结果要为0。 System.out.println(i + ": " + a + "/" + b + "="); int c0 = in.nextInt(); out.println(a + "/" + b + "=" + c0); if (c0 == counter.division(a, b)) { sum += 10; System.out.println("right!"); } else { System.out.println("error!"); } break; case 2: System.out.println(i + ": " + a + "*" + b + "="); int c = in.nextInt(); out.println(a + "*" + b + "=" + c); if (c == counter.multiplication(a, b)) { sum += 10; System.out.println("right!"); } else { System.out.println("error!"); } break; case 3: System.out.println(i + ": " + a + "+" + b + "="); int c1 = in.nextInt(); out.println(a + "+" + b + "=" + c1); if (c1 == counter.add(a, b)) { sum += 10; System.out.println("right!"); } else { System.out.println("error!"); } break; case 4: while (a < b) { b = (int) Math.round(Math.random() * 100); } //因为不能产生运算结果为负数的减法式子,所以a一定要大于b。若a<b,则重新生成b。 System.out.println(i + ": " + a + "-" + b + "="); int c2 = in.nextInt(); out.println(a + "-" + b + "=" + c2); if (c2 == counter.reduce(a, b)) { sum += 10; System.out.println("right!"); } else { System.out.println("error!"); } break; } } System.out.println("成绩" + sum); out.println("成绩:" + sum); out.close(); } }
package demo; public class yunsuan<T> { private T a; private T b; public yunsuan() { a = null; b = null; } public yunsuan(T a, T b) { this.a = a; this.b = b; } public int add(int a,int b) { return a + b; } public int reduce(int a, int b) { return a - b; } public int multiplication(int a, int b) { return a * b; } public int division(int a, int b) { if (b != 0 && a%b==0) return a / b; else return 0; } }
采用结对编程方式,与学习伙伴合作完成实验九编程练习1
import java.io; 2 import java.io.File; 3 import java.io.FileInputStream; 4 import java.io.FileNotFoundException; 5 import java.io.IOException; 6 import java.io.InputStreamReader; 7 import java.util.ArrayList; 8 import java.util.Arrays; 9 import java.util.Collections; 10 import java.util.Scanner; 11 12 public class Test{ 13 private static ArrayList<Student> studentlist; 14 public static void main(String[] args) { 15 studentlist = new ArrayList<>(); 16 Scanner scanner = new Scanner(System.in); 17 File file = new File("C:\\下载\\身份证号.txt"); 18 try { 19 FileInputStream fis = new FileInputStream(file); 20 BufferedReader in = new BufferedReader(new InputStreamReader(fis)); 21 String temp = null; 22 while ((temp = in.readLine()) != null) { 23 24 Scanner linescanner = new Scanner(temp); 25 26 linescanner.useDelimiter(" "); 27 String name = linescanner.next(); 28 String number = linescanner.next(); 29 String sex = linescanner.next(); 30 String age = linescanner.next(); 31 String province =linescanner.nextLine(); 32 Student student = new Student(); 33 student.setName(name); 34 student.setnumber(number); 35 student.setsex(sex); 36 int a = Integer.parseInt(age); 37 student.setage(a); 38 student.setprovince(province); 39 studentlist.add(student); 40 41 } 42 } catch (FileNotFoundException e) { 43 System.out.println("学生信息文件找不到"); 44 e.printStackTrace(); 45 } catch (IOException e) { 46 System.out.println("学生信息文件读取错误"); 47 e.printStackTrace(); 48 } 49 boolean isTrue = true; 50 while (isTrue) { 51 System.out.println("选择你的操作,输入正确格式的选项"); 52 System.out.println("1.按姓名字典序输出人员信息"); 53 System.out.println("2.输出年龄最大和年龄最小的人"); 54 System.out.println("3.查找老乡"); 55 System.out.println("4.查找年龄相近的人"); 56 System.out.println("5.退出"); 57 String m = scanner.next(); 58 switch (m) { 59 case "1": 60 Collections.sort(studentlist); 61 System.out.println(studentlist.toString()); 62 break; 63 case "2": 64 int max=0,min=100; 65 int j,k1 = 0,k2=0; 66 for(int i=1;i<studentlist.size();i++) 67 { 68 j=studentlist.get(i).getage(); 69 if(j>max) 70 { 71 max=j; 72 k1=i; 73 } 74 if(j<min) 75 { 76 min=j; 77 k2=i; 78 } 79 80 } 81 System.out.println("年龄最大:"+studentlist.get(k1)); 82 System.out.println("年龄最小:"+studentlist.get(k2)); 83 break; 84 case "3": 85 System.out.println("输入省份"); 86 String find = scanner.next(); 87 String place=find.substring(0,3); 88 for (int i = 0; i <studentlist.size(); i++) 89 { 90 if(studentlist.get(i).getprovince().substring(1,4).equals(place)) 91 System.out.println("老乡"+studentlist.get(i)); 92 } 93 break; 94 95 case "4": 96 System.out.println("年龄:"); 97 int yourage = scanner.nextInt(); 98 int near=agenear(yourage); 99 int value=yourage-studentlist.get(near).getage(); 100 System.out.println(""+studentlist.get(near)); 101 break; 102 case "5": 103 isTrue = false; 104 System.out.println("退出程序!"); 105 break; 106 default: 107 System.out.println("输入有误"); 108 109 } 110 } 111 } 112 public static int agenear(int age) { 113 int j=0,min=53,value=0,k=0; 114 for (int i = 0; i < studentlist.size(); i++) 115 { 116 value=studentlist.get(i).getage()-age; 117 if(value<0) value=-value; 118 if (value<min) 119 { 120 min=value; 121 k=i; 122 } 123 } 124 return k; 125 } 126 127 }
public class Student implements Comparable<Student> { 2 3 private String name; 4 private String number ; 5 private String sex ; 6 private int age; 7 private String province; 8 9 public String getName() { 10 return name; 11 } 12 public void setName(String name) { 13 this.name = name; 14 } 15 public String getnumber() { 16 return number; 17 } 18 public void setnumber(String number) { 19 this.number = number; 20 } 21 public String getsex() { 22 return sex ; 23 } 24 public void setsex(String sex ) { 25 this.sex =sex ; 26 } 27 public int getage() { 28 29 return age; 30 } 31 public void setage(int age) { 32 // int a = Integer.parseInt(age); 33 this.age= age; 34 } 35 36 public String getprovince() { 37 return province; 38 } 39 public void setprovince(String province) { 40 this.province=province ; 41 } 42 43 public int compareTo(Student o) { 44 return this.name.compareTo(o.getName()); 45 } 46 47 public String toString() { 48 return name+" "+sex+" "+age+" "+number+" "+province+" "; 49 } 50 }
采用结对编程方式,与学习伙伴合作完成实验十编程练习2
package XOI;
import java.util.Random;
import java.util.Scanner;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
public class Main{
public static void main(String[] args)
{
yunsuan counter=new yunsuan();//与其它类建立联系
PrintWriter out=null;
try {
out=new PrintWriter("D:/text.txt");//将文件里的内容读入到D盘名叫text
}catch(FileNotFoundException e) {
System.out.println("文件找不到");
e.printStackTrace();
}
int sum=0;
for(int i=0;i<10;i++)
{
int a=new Random().nextInt(100);
int b=new Random().nextInt(100);
Scanner in=new Scanner(System.in);
//in.close();
switch((int)(Math.random()*4))
{
case 0:
System.out.println( ""+a+"+"+b+"=");
int c1 = in.nextInt();
out.println(a+"+"+b+"="+c1);
if (c1 == counter.plus(a, b)) {
sum += 10;
System.out.println("答案正确");
}
else {
System.out.println("答案错误");
}
break ;
case 1:
if(a<b)
{
int temp=a;
a=b;
b=temp;
}//为避免减数比被减数大的情况
System.out.println(""+a+"-"+b+"=");
/*while((a-b)<0)
{
b = (int) Math.round(Math.random() * 100);
}*/
int c2 = in.nextInt();
out.println(a+"-"+b+"="+c2);
if (c2 == counter.minus(a, b)) {
sum += 10;
System.out.println("答案正确");
}
else {
System.out.println("答案错误");
}
break ;
case 2:
System.out.println(""+a+"*"+b+"=");
int c = in.nextInt();
out.println(a+"*"+b+"="+c);
if (c == counter.multiply(a, b)) {
sum += 10;
System.out.println("答案正确");
}
else {
System.out.println("答案错误");
}
break;
case 3:
while(b==0)
{ b = (int) Math.round(Math.random() * 100);//满足分母不为0
}
while(a%b!=0)
{
a = (int) Math.round(Math.random() * 100);
b = (int) Math.round(Math.random() * 100);
}
System.out.println(""+a+"/"+b+"=");
int c0= in.nextInt();
out.println(a+"/"+b+"="+c0);
if (c0 == counter.divide(a, b)) {
sum += 10;
System.out.println("答案正确");
}
else {
System.out.println("答案错误");
}
break;
}
}
System.out.println("totlescore:"+sum);
out.println(sum);
out.close();
}
}
package XOI;
public class yunsuan <T>{
private T a;
private T b;
public void yunsaun()
{
a=null;
b=null;
}
public void yunsuan(T a,T b)
{
this.a=a;
this.b=b;
}
public int plus(int a,int b)
{
return a+b;
}
public int minus(int a,int b)
{
return a-b;
}
public int multiply(int a,int b)
{
return a*b;
}
public int divide(int a,int b)
{
if(b!=0 && a%b==0)
return a/b;
else
return 0;
}
}
实验总结:这次实验通过互相学习感受自己和别人所写代码的不同相互学习进行比较。
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