用c语言实现把任意给定的俩个一元多项式P（x），Q（x）输入计算机，计算他们的和并输出就算结果

好的，我可以帮您解决这个问题。

首先，我们需要定义一元多项式的数据结构。可以使用链表来实现，每个节点代表一项，包含系数和指数两个成员。

typedef struct polyNode {
    float coef;
    int expn;
    struct polyNode *next;
} PolyNode, *Polynomial;

然后，我们可以编写一个函数来输入一元多项式：

Polynomial createPoly() {
    Polynomial head, tail, p;
    int n, i;
    float c;
    head = (Polynomial)malloc(sizeof(PolyNode));
    head->next = NULL;
    tail = head;
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        p = (Polynomial)malloc(sizeof(PolyNode));
        scanf("%f %d", &c, &p->expn);
        p->coef = c;
        tail->next = p;
        tail = p;
    }
    tail->next = NULL;
    return head;
}

该函数会读取输入的项数，然后依次读入每一项的系数和指数，构建一个一元多项式。返回值为该多项式的头节点。

接下来，我们可以编写一个函数来计算两个多项式的和：

Polynomial addPoly(Polynomial P, Polynomial Q) {
    Polynomial head, tail, p1, p2, tmp;
    float c;
    head = (Polynomial)malloc(sizeof(PolyNode));
    head->next = NULL;
    tail = head;
    p1 = P->next;
    p2 = Q->next;
    while (p1 && p2) {
        if (p1->expn == p2->expn) {
            c = p1->coef + p2->coef;
            if (c != 0) {
                tmp = (Polynomial)malloc(sizeof(PolyNode));
                tmp->coef = c;
                tmp->expn = p1->expn;
                tail->next = tmp;
                tail = tmp;
            }
            p1 = p1->next;
            p2 = p2->next;
        }
        else if (p1->expn > p2->expn) {
            tmp = (Polynomial)malloc(sizeof(PolyNode));
            tmp->coef = p1->coef;
            tmp->expn = p1->expn;
            tail->next = tmp;
            tail = tmp;
            p1 = p1->next;
        }
        else {
            tmp = (Polynomial)malloc(sizeof(PolyNode));
            tmp->coef = p2->coef;
            tmp->expn = p2->expn;
            tail->next = tmp;
            tail = tmp;
            p2 = p2->next;
        }
    }
    while (p1) {
        tmp = (Polynomial)malloc(sizeof(PolyNode));
        tmp->coef = p1->coef;
        tmp->expn = p1->expn;
        tail->next = tmp;
        tail = tmp;
        p1 = p1->next;
    }
    while (p2) {
        tmp = (Polynomial)malloc(sizeof(PolyNode));
        tmp->coef = p2->coef;
        tmp->expn = p2->expn;
        tail->next = tmp;
        tail = tmp;
        p2 = p2->next;
    }
    tail->next = NULL;
    return head;
}

该函数会遍历两个多项式，依次将相同指数的项相加，并将结果构建成一个新的多项式。返回值为该多项式的头节点。

最后，我们可以编写主函数来调用以上两个函数，并输出结果：

int main() {
    Polynomial P, Q, R;
    P = createPoly();
    Q = createPoly();
    R = addPoly(P, Q);
    while (R->next) {
        R = R->next;
        printf("%.1fx^%d ", R->coef, R->expn);
        if (R->next && R->next->coef > 0) {
            printf("+ ");
        }
    }
    return 0;
}

该函数会先输入两个多项式 P 和 Q，然后调用 addPoly 函数计算它们的和，最后遍历输出结果。