C语言，一元多项式相加，链式结构

在C语言中，一元多项式通常通过链表结构来表示，每个节点包含系数和变量指数，可以方便地实现相加操作。下面是一个简单的示例，展示了如何使用链表结构表示一元多项式以及它们之间的相加：

首先，定义一个链表节点的结构体：

typedef struct PolynomialTerm {
    float coefficient; // 系数
    int exponent;       // 指数
    struct PolynomialTerm* next; // 指向下一个项的指针
} PolynomialTerm;

接着，创建一个函数来创建一个新的链表节点：

PolynomialTerm* createTerm(float coef, int exp) {
    PolynomialTerm* term = (PolynomialTerm*)malloc(sizeof(PolynomialTerm));
    term->coefficient = coef;
    term->exponent = exp;
    term->next = NULL;
    return term;
}

然后，定义一个函数来进行两个多项式的相加：

void addTerms(PolynomialTerm** result, PolynomialTerm* a, PolynomialTerm* b) {
    PolynomialTerm* current_a = a, *current_b = b, *new_head = NULL;

    while (a && b) {
        PolynomialTerm* new_term = createTerm(current_a->coefficient + current_b->coefficient, max(current_a->exponent, current_b->exponent));
        if (!new_head) {
            new_head = new_term;
        } else {
            current_result->next = new_term;
        }
        current_a = current_a->next;
        current_b = current_b->next;
    }

    // 处理剩余项（如果存在）
    while (current_a) {
        PolynomialTerm* new_term = createTerm(current_a->coefficient, current_a->exponent);
        if (!new_head) {
            new_head = new_term;
        } else {
            current_result->next = new_term;
        }
        current_a = current_a->next;
    }

    while (current_b) {
        PolynomialTerm* new_term = createTerm(current_b->coefficient, current_b->exponent);
        if (!new_head) {
            new_head = new_term;
        } else {
            current_result->next = new_term;
        }
        current_b = current_b->next;
    }

    *result = new_head;
}

最后，在主函数中使用上述函数：

int main() {
    PolynomialTerm* poly1 = createTerm(2.0f, 2);   // 2x^2
    PolynomialTerm* poly2 = createTerm(-1.0f, 1);  // -x

    PolynomialTerm* result = NULL;
    addTerms(&result, poly1, poly2);

    // 打印结果多项式
    PolynomialTerm* temp = result;
    while (temp) {
        printf("%.1fx^%d -> ", temp->coefficient, temp->exponent);
        temp = temp->next;
    }
    printf("\n");

    return 0;
}