结对项目

def generate_problem(r):
    # 确保不产生负数和符合真分数要求
    operators = {
        '+': operator.add,
        '-': operator.sub,
        '*': operator.mul,
        '/': operator.truediv
    }

    # 随机生成运算符个数（1到3个）
    num_operators = random.randint(1, 3)
    terms = []

    for _ in range(num_operators + 1):  # 生成操作数
        if random.choice([True, False]):  # 50%概率选择自然数
            term = random.randint(1, r)
        else:  # 50%概率选择分数
            numerator = random.randint(1, r)
            denominator = random.randint(1, r) + 1  # 确保分母不为0
            term = Fraction(numerator, denominator)
        terms.append(term)

    # 随机选择运算符
    expression = str(terms[0])
    for i in range(num_operators):
        op = random.choice(list(operators.keys()))
        expression += f" {op} {terms[i + 1]}"

    # 计算结果
    try:
        result = problem_eval(expression) 
    except ZeroDivisionError:
        return generate_problem(r)  # 重新生成题目以避免除以零

    # 检查结果
    if result < 0 or (result.denominator != 1 and result.numerator < 0):
        return generate_problem(r)  # 重新生成题目以避免负数

    # 格式化结果为真分数形式
    formatted_result = format_fraction(result)
    expression = expression.replace('*', '×')
    if re.search(r'\s/\s', expression):
        expression = re.sub(r'\s/\s', ' ÷ ', expression)

    return expression, formatted_result

def calculate_answer(exercise):
    exercise = exercise.strip().split('. ')[1]  # 移除题号

    # 匹配分数或整数
    elements = re.findall(r'\d+/\d+|\d+', exercise)  # 匹配分数或整数
    operators = re.findall(r'\s[+\-*/]\s', exercise)  # 匹配运算符

    # 将匹配的数字或分数转换为 Fraction 对象
    fractions = [Fraction(e) for e in elements]

    # 使用两个栈来处理运算符优先级
    values = []
    ops = []

    for i in range(len(fractions)):
        values.append(fractions[i])

        if i < len(operators):
            op = operators[i].strip()
            while ops and precedence(op) <= precedence(ops[-1]):
                # if len(values) < 2:  # 确保有足够的值进行运算
                #     break
                right = values.pop()
                left = values.pop()
                operator = ops.pop()
                values.append(apply_operator(left, right, operator))
            ops.append(op)

    # 处理剩余的运算符
    while ops:
        right = values.pop()
        left = values.pop()
        operator = ops.pop()
        values.append(apply_operator(left, right, operator))

    return values[0]  # 返回格式化后的结果