软工第三次作业-结对项目

软工第三次作业

小组成员
3123004287肖锦瑞
3123004268黄泽鹏

Github 仓库链接

这个作业属于哪个课程	软件工程
这个作业要求在哪里作业要求	作业要求
这个作业的目标	实现一个自动生成小学四则运算题目的命令行程序

PSP 表格

Personal Software Process Stages	预估耗时（分钟）	实际耗时（分钟）
计划	15	20
估计这个任务需要多少开发时间	10	15
开发	600	700
需求分析（包括学习新技术）	60	65
生成设计文档	20	25
设计复审	30	35
代码规范（为目前的开发制定合适的规范）	20	25
具体设计	30	35
具体编码	60	60
代码复审	20	25
测试（自我测试，修改代码，提交代码）	30	60
报告	30	35
测试报告	20	25
计算工作量	10	15
事后总结	15	20
合计	700	830

计算模块接口的设计与实现过程

计算结果的核心思想

利用栈数据结构，先进后出原则

方法：用两个栈(一个用于保存运算符，一个用于保存操作数)，其中的运算符包括：+,-,*,/,(,),

表达式有括号、运算符、和操作数(数字)组成。我们根据以下4种情况从左到右逐个将这些实体送入栈处理

1，将操作数压入操作数栈

2，将运算符压入运算符栈

3，忽略左括号

4，在遇到右括号时，弹出一个运算符，弹出所需数量的操作数，并将运算符和操作数的运算结果压入操作数栈

最后:

在处理完最后一个右括号的时候，操作数栈中只会又一个值，他就是表达式的值

程序流程图

各模块具体实现代码

计算模块

public class Calculation {//设置运算符的优先级public static Map<String, Integer> map = new HashMap<String, Integer>() {/*** */private static final long serialVersionUID = 3684443232637633564L;{put("(", 0);put("+", 1);put("-", 1);put("×", 2);put("÷", 2);put(")", 3);put("=", 4);}};//将最终结果进行格式化public static String finalResult(String num) throws Exception {String[] nums = new String[2];int mole, deno;nums = FractionCalculation.change(num);mole = Integer.parseInt(nums[0]);deno = Integer.parseInt(nums[1]);String finalResult = FormatProcess.Format(mole, deno);if(finalResult.contains("-")) {//部分运算结果为负数throw new Exception();}else {return finalResult;}}// 括号内运算符的优先级是从低到高public static void doCalcul(Stack<String> operaStack, Stack<String> numStack, boolean flag) throws Exception {//将两个数值及运算符出栈进行计算String nowOpera = operaStack.pop();String nowNum_2 = numStack.pop();String nowNum_1 = numStack.pop();String result = FractionCalculation.result(nowOpera, nowNum_1, nowNum_2);			if(result.contains("-")) {	//结果为负										throw new Exception();}else {numStack.push(result);			}if(flag) {if("(".equals(operaStack.peek())) {//栈顶为（operaStack.pop();}else {doCalcul(operaStack, numStack, flag);//栈顶不为“（”}}else {if(!operaStack.empty()) {							doCalcul(operaStack, numStack, flag);}}}// 优先级比较public static void comparePriority(Stack<String> operaStack, Stack<String> numStack, String operator) throws Exception{String topOpera = operaStack.peek();int priority = map.get(operator) - map.get(topOpera);//优先级判断if (priority > 0) {operaStack.push(operator);} else {String nowOpera = operaStack.pop();String nowNum_2 = numStack.pop();String nowNum_1 = numStack.pop();String result = FractionCalculation.result(nowOpera, nowNum_1, nowNum_2);numStack.push(result);if (operaStack.empty()) {//运算符栈为空operaStack.push(operator);} else {comparePriority(operaStack, numStack, operator);}}}	
}

题目生成模块

//生成题目及计算出答案
public class GenerateItem {public static void createitem(int range, int num) {String operator[] = { "+", "-", "×", "÷" };String allAnswer = "";	//全部答案String allItems = "";	//全部题目for(int i = 0;i < num;i++) {int operatornum = (int) (Math.random() * 3 + 1);String figure = null, operate = null;int undo = 0;int bracketnum = 0;String expression = "";boolean flag = true;String result;Stack<String> operaStack = new Stack<String>();Stack<String> numStack = new Stack<String>();try {// 未包含最后一个数while (operatornum > 0) {int tag = (int) (Math.random() * 2);			//用于判断是否要生成括号figure = FormatProcess.fraction(range);operate = operator[(int) (Math.random() * 4)];if (tag == 0 && bracketnum < operatornum - 1) {expression += "(";operaStack.push("(");bracketnum++;undo++;flag = false;} else if (tag == 1&& flag == true && undo > 0) {expression += figure + ")" + " " + operate + " ";numStack.push(figure);Calculation.doCalcul(operaStack, numStack, true);Calculation.comparePriority(operaStack, numStack, operate);operatornum--;undo--;flag = false;} else { expression += figure + " " + operate + " ";if (operaStack.empty()) {operaStack.push(operate);numStack.push(figure);} else {numStack.push(figure);Calculation.comparePriority(operaStack, numStack, operate);}operatornum--;flag = true;}}// 添加最后一个数if (undo == 0) {figure = FormatProcess.fraction(range);expression += figure;} else if (undo == 1) {if (expression.startsWith("((") || expression.startsWith("(") && expression.contains(")") == false) {figure = FormatProcess.fraction(range);expression = expression.substring(1) + figure;} else {figure = FormatProcess.fraction(range);expression += figure + ")";}} else if (undo == 2) {if (expression.startsWith("((")) {figure = FormatProcess.fraction(range);expression = expression.substring(2) + figure;} else if (expression.startsWith("(")) {figure = FormatProcess.fraction(range);expression = expression.substring(1) + figure + ")";} else {figure = FormatProcess.fraction(range);expression += figure + "))";}}numStack.push(figure);Calculation.doCalcul(operaStack, numStack, false);result = Calculation.finalResult(numStack.peek());expression += " " + "=";if(expression.contains("÷ 0")) {i--;expression = "";}else {allItems +=   (i + 1) + "、  " + expression + "\n" ;allAnswer +=  (i + 1) + "、  " + result + "\n" ;}} catch (Exception e) {// TODO: handle exceptioni--;}}FileOutPut.FileOutPut(allItems, 1);FileOutPut.FileOutPut(allAnswer, 2);}
}

分数计算模块

public class FractionCalculation {public static String result(String nowOpera, String nowNum_1, String nowNum_2){String result = null;int mole_1, deno_1, mole_2, deno_2;String[] value_1 = change(nowNum_1);		mole_1 = Integer.parseInt(value_1[0]);deno_1 = Integer.parseInt(value_1[1]);String[] value_2 = change(nowNum_2);mole_2 = Integer.parseInt(value_2[0]);deno_2 = Integer.parseInt(value_2[1]);int flag = 0;if(nowOpera=="+") flag=1;else if(nowOpera=="-") flag=2;else if(nowOpera=="×") flag=3;else if(nowOpera=="÷") flag=4;switch (flag) {case 1:result = add(mole_1, deno_1, mole_2, deno_2);break;case 2:result = subtraction(mole_1, deno_1, mole_2, deno_2);break;case 3:result = multiplication(mole_1, deno_1, mole_2, deno_2);break;case 4:result = division(mole_1, deno_1, mole_2, deno_2);break;default:break;}			return result;			}	//加法public static String add(int a, int b, int c, int d) {int mole, deno;mole = a * d + c * b;deno = b * d;	return mole + "/" + deno;}//减法public static String subtraction(int a, int b, int c, int d){int mole, deno;mole = a * d - c * b;deno = b * d;return mole + "/" + deno;}//乘法public static String multiplication(int a, int b, int c, int d) {int mole, deno;mole = a * c;deno = b * d;return mole + "/" + deno;}//除法public static String division(int a, int b, int c, int d) {int mole, deno;mole = a * d;deno = b * c;return mole + "/" + deno;}//将分数转换成a/b形式并将a、b添加进array数组中public static String[] change(String num){String [] array = new String [2];if(num.contains("/")) {if(num.contains("'")) {//带分数String[] tarray = num.split("/|'");int[] sarray = new int[3];for(int i = 0;i<3;i++) {sarray[i] = Integer.parseInt(tarray[i]);}					array[0] = String.valueOf(sarray[0] * sarray[2] + sarray[1]);array[1] = String.valueOf(sarray[2]);			}else {					array = num.split("/");				}}else {array[0] = num;array[1] = "1";}return array;}		
}

格式处理模块

//格式处理
public class FormatProcess {public static String fraction(int range) {int mole, deno;mole = (int) (Math.random() * range);deno = (int) (Math.random() * range + 1);return Format(mole, deno);}public static String Format(int mole, int deno) {String fraction = null;int min = 0;min = (mole > deno)   ? deno : mole;if (mole == 0) {fraction = "0";} else if (mole % deno == 0) {fraction = String.valueOf(mole / deno);} else {for (int i = min; i >= 2; i--) {if (mole % i == 0 && deno % i == 0) {mole = mole / i;deno = deno / i;}}if (mole > deno) {fraction = String.valueOf(mole / deno) + "'" + String.valueOf(mole % deno) + "/" + String.valueOf(deno);} else {fraction = mole + "/" + deno;}}return fraction;}
}

文件输出保存模块

public class FileOutPut {public static void FileOutPut(String str, int tag) {String path = "";if(tag == 1) {path = "D:\\Exercises.txt";}else if(tag == 2){path = "D:\\Answers.txt";}File file = new File(path);FileWriter fw;try {fw = new FileWriter(file,false);fw.write(str);fw.close();System.out.println("文件保存成功！");} catch (IOException e) {// TODO Auto-generated catch blockSystem.out.println("文件保存不成功！");}}}

main方法

public class PairPro {public static void main(String[] args) {// TODO Auto-generated method stubint i=args.length;int num,range;long startTime = 0,endTime = 0;if(i==4) {//从命令行接收四个参数 -n,num,-r,rangeif(args[0]=="-n"&&args[2]=="-r") {//生成题目if(isNumeric(args[1])==true&&isNumeric(args[3])==true) {num=Integer.valueOf(args[1]);range=Integer.valueOf(args[3]);if(num>0&&range>0) {startTime = System.currentTimeMillis();GenerateItem.createitem(range, num);endTime = System.currentTimeMillis();}else {System.out.println("您输入的参数不合法！！！");System.exit(0);}}}else {System.out.println("您输入的参数不合法！！！");System.exit(0);}}else{System.out.println("您输入的参数数目不符合要求");System.exit(0);}System.out.println("程序运行时间：" + (endTime - startTime) + "ms");}//正则纯数字判断public static boolean isNumeric(String str) {Pattern pattern = Pattern.compile("[0-9]*");Matcher isNum = pattern.matcher(str);if (!isNum.matches()) {return false;}return true;}}

运行结果

代码优化

·加入检查题目是否重复的模块
·加入答案检查模块

性能分析

cpu性能分析

字符和字符串型数据占用大量资源

个人总结

肖锦瑞
优点：二人结对编程情况下会比较认真负责，遇到不懂就一起在网上找资料一起学习
缺点：代码风格不同，组合代码时效率较差
黄泽鹏
优点：两个合作，想法更丰富，多元，计划制定更完善，资料查找更全面，工作量降低，能互相学习对方的写代码优点，专注自己擅长的部分，弱势部分由队友补足。
不足：没有建立良好的沟通渠道，沟通成本较高，没有建立良好统一的代码规范，后期管理会比较麻烦。