20172319 2018.04.23-05.02

Pair programming exercise _ four arithmetic operations

Phase 1 summary of the first week

content

paired object
demand analysis
Design ideas
Pair evaluation
PSP
References

Pairing objects:

20172316 Zhao Ganchen (driver, navigator)
20172319 Tang Caiming (driver, navigator)
20172319 Wang Wenbin (driver, navigator)

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demand analysis:

1. Project content

Write code in paired groups to:

1. Automatically generate questions
Can be used independently (can realize the function of writing test classes to generate questions independently),
and can generate questions of different levels, similar to:
Level 1 questions: two numbers such as 2 + 5 =
10 - 5 =
, one operator title

2. The question operation (judgment)
can be used independently to
realize the conversion of infix expressions into postfix expressions and to calculate
the correctness of the user's answer and output the correct result

3. Support true fractions,
which can be used independently to
realize the calculation of fractional formulas

4. Topic de-duplication (expansion requirements, bonus items)
can be used independently to
achieve de-duplication of automatically generated expressions: as follows
If generated: 2 + 5 =
5 + 2 =
the same topic

2. Understand:

Can randomly generate n four arithmetic problems, n is input by the user
Supports whole numbers and fractions
Support multiple operators, the number of operators can be input by the user
Able to judge right and wrong, remind and output the correct answer when wrong
Correct rate can be calculated

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Design ideas:

Due to the difference in the division of labor, individuals complete various parts of the project independently, and I am responsible for supporting the true score part;

To operate on two fractions, the question must be random. It must be considered that the numerator and denominator of each are random, so four variables are set. Each variable is randomly selected from (-50) to (50). number
Declare a String class variable to evaluate and output the operator

 switch (e)  //  运算符号
        {
            case 0:
                s1 = " ＋ ";
                break;
            case 1:
                s1 = " － ";
                break;
            case 2:
                s1 = " × ";
                break;
            case 3:
                s1 = " ÷ ";
                break;
        }

then toString outputs the equation

s2 = numerator1/denominator1 + s1 + numerator2/denominator2 + " ＝ ";

However, I encountered a problem. Although the output is a fraction, it does not satisfy the
true fraction. In order to ensure that the fraction operation is a true fraction

while (true) {
            numerator1 = generactor.nextInt(51) - 50;
            denominator1 = generactor.nextInt(51) - 50;
            numerator2 = generactor.nextInt(51) - 50;
            denominator2 = generactor.nextInt(51) - 50;
            e = (int)(Math.random()*4);

            a = numerator1;
            b = denominator1;
            c = numerator2;
            d = denominator2;

            if (numerator1 >= denominator1 || numerator2 >= denominator2||denominator1==0||denominator2==0||numerator2==0) //  保证真分数（分子分母不为0，分子小于分母）
                continue;
            else {
                    do {
                        h = a % b;
                        i = c % d;
                        a = b;
                        c = d;
                        b = h;
                        d = i;
                    } while (h != 0 && i != 0);
        }

The method of tossing and dividing is used to ensure that the numerator and denominator are mutually prime, thereby ensuring the
true fraction

Class Diagram:

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Pair evaluation:

Although they both have pilots and pilots, they only cooperate in certain aspects. Personal coding style and code are not commented, so sometimes they cannot understand what their partners write. Each purpose can be achieved independently, but there is no connection for the time being. into a whole.

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PSP：

PSP2.1	Personal Software Process Stages	Estimated time (minutes)	Actual time (minutes)
Planning	plan	60	60
Estimate	Estimate how long this task will take	100	100
Development	develop	800
Analysis	Requirements analysis (including learning new technologies)	100	60
Coding Standard	Code Specifications (to develop appropriate specifications for current development)	30	20
Design UML	Design project UML class diagram	50	30
Coding	specific code	30
Code Review	code review	50
Test	Testing (self-testing, modifying code, committing changes)	30
Size Measurement	Computational workload (actual time	30
Postmortem & Process Improvement Plan	Post-event summary, and propose a process improvement plan	30
	total	1240