请给出完整的各个函数的C语言代码

为了实现完整的功能，我们需要几个关键的函数，包括输入多项式、输出多项式、加法、减法、乘法和导数的计算。以下是这些函数的基本C语言实现，注意这些代码只是一个简化版本，实际应用中可能需要考虑更多边界条件和错误处理：

// 添加项到多项式链表
void add_term(Polynomial* poly, double coefficient, int exponent) {
    Term* new_term = (Term*)malloc(sizeof(Term));
    new_term->coefficient = coefficient;
    new_term->exponent = exponent;
    if (!poly->terms) {
        poly->terms = new_term;
    } else {
        Term* curr = poly->terms;
        while (curr->next && curr->exponent < exponent) {
            curr = curr->next;
        }
        if (curr->next) {
            curr->next->previous = new_term;
        }
        new_term->next = curr->next;
        curr->next = new_term;
        if (new_term->next) {
            new_term->next->previous = new_term;
        }
    }
    poly->size++;
}

// 输入多项式到链表
void input_polynomial_from_file(Polynomial* poly, const char* filename) {
    // 打开文件
    FILE* file = fopen(filename, "r");
    if (!file) {
        perror("Error opening file");
        return;
    }

    // 逐行读取数据并添加到多项式
    char line[100];
    while (fgets(line, sizeof(line), file)) {
        char* end;
        double coefficient = strtod(line, &end);
        int exponent = atoi(end);
        add_term(poly, coefficient, exponent);
    }
    fclose(file);
}

// 输出多项式到文件
void output_polynomial_to_file(const Polynomial* poly, const char* filename) {
    FILE* file = fopen(filename, "w");
    if (!file) {
        perror("Error opening file");
        return;
    }

    for (Term* term = poly->terms; term != NULL; term = term->next) {
        fprintf(file, "%.2f*x^%d\n", term->coefficient, term->exponent);
    }
    fclose(file);
}

// 加法和减法操作
Polynomial* add_or_subtract(Polynomial* poly1, Polynomial* poly2, char op) {
    Polynomial* result = create_polynomial();
    
    if (op == '+') {
        for (Term* term1 = poly1->terms; term1 != NULL; term1 = term1->next) {
            Term* found = find_term_in_poly(result, term1->exponent);
            if (found) {
                found->coefficient += term1->coefficient;
            } else {
                add_term(result, term1->coefficient, term1->exponent);
            }
        }
    } else if (op == '-') {
        for (Term* term1 = poly1->terms; term1 != NULL; term1 = term1->next) {
            Term* found = find_term_in_poly(result, term1->exponent);
            if (found) {
                found->coefficient -= term1->coefficient;
            } else {
                add_term(result, -term1->coefficient, term1->exponent);
            }
        }
    } else {
        printf("Invalid operator.\n");
        return NULL;
    }

    return result;
}

// 查找并替换现有项
Term* find_term_in_poly(Polynomial* poly, int exponent) {
    Term* curr = poly->terms;
    while (curr && curr->exponent != exponent) {
        curr = curr->next;
    }
    return curr;
}

// 乘法操作
Polynomial* multiply_polynomials(Polynomial* poly1, Polynomial* poly2) {
    Polynomial* result = create_polynomial();
    for (Term* term1 = poly1->terms; term1 != NULL; term1 = term1->next) {
        for (Term* term2 = poly2->terms; term2 != NULL; term2 = term2->next) {
            int combined_exponent = term1->exponent + term2->exponent;
            double product = term1->coefficient * term2->coefficient;
            add_term(result, product, combined_exponent);
        }
    }
    return result;
}

// 导数计算，这里简化为每一项乘以指数减一
Polynomial* calculate_derivative(const Polynomial* poly, int order) {
    Polynomial* derivative = create_polynomial();
    for (Term* term = poly->terms; term != NULL; term = term->next) {
        double derivative_value = term->coefficient * order;
        if (derivative_value != 0) {
            add_term(derivative, derivative_value, term->exponent - 1);
        }
    }
    return derivative;
}

这只是一个基础示例，实际操作中可能需要考虑更复杂的细节，例如处理分母为零的除法情况、优化乘法操作等。