void InitPolylist(Polylist *L) { (*L) = NULL; } Polylist CreatePolylist() { Polylist L=NULL, p=NULL, q=NULL; double c; int e; InitPolylist(&L); scanf("%lf%d", &c, &e); while (c != 0) { p=(Polylist)malloc(sizeof(Polynode)); p->coef=c; p->exp=e; p->next=NULL; if(L==NULL) { L=p; } else { q=L; while(q->next!=NULL) q=q->next; q->next=p; } scanf("%lf%d", &c, &e); } return L; } int LengthPolylist(Polylist L) { int n=0; Polylist p=L; while(p!=NULL) { n++; p=p->next; } return n; } void OutputPolylist(Polylist L) { Polylist p=L; if(p!=NULL) { OutputPolylist(p->next); printf("%.2f,%d", p->coef, p->exp); } printf("\n"); } Polylist AddPolylist() { Polylist A=NULL, B=NULL, C=NULL, p=NULL, q=NULL, r=NULL; A=CreatePolylist(); B=CreatePolylist(); InitPolylist(&C); p=A; q=B; while(p!=NULL && q!=NULL) { if(p->exp<q->exp) { r=(Polylist)malloc(sizeof(Polynode)); r->coef=q->coef; r->exp=q->exp; r->next=C; C=r; q=q->next; } else { if(p->exp==q->exp) { if(fabs(p->coef + q->coef)>1e-6) { r=(Polylist)malloc(sizeof(Polynode)); r->coef=p->coef+q->coef; r->exp=p->exp; r->next=C; C=r; } p=p->next; q=q->next; } else { r=(Polylist)malloc(sizeof(Polynode)); r->coef=p->coef; r->exp=p->exp; r->next=C; C=r; p=p->next; } } } while(p!=NULL) { r=(Polylist)ma

lloc(sizeof(Polynode)); r->coef=p->coef; r->exp=p->exp; r->next=C; C=r; p=p->next; } while(q!=NULL) { r=(Polylist)malloc(sizeof(Polynode)); r->coef=q->coef; r->exp=q->exp; r->next=C; C=r; q=q->next; } return C; }

请问这段代码实现了什么功能？

相关问题

void·InitPolylist(Polylist·*L)函数的意思和作用

函数 `void InitPolylist(Polylist *L)` 的作用是对一个多项式链表进行初始化，即将其头结点的各个指针域全部置为 NULL，表示该链表为空。

其中，`Polylist` 是一个结构体类型，定义了多项式链表的结构，包括：

- `PolyNode *head`：指向链表头结点的指针；
- `PolyNode *tail`：指向链表尾结点的指针；
- `int len`：链表的长度。

而 `PolyNode` 结构体则定义了多项式链表的结点，包括：

- `double coef`：结点的系数；
- `int expn`：结点的指数；
- `PolyNode *next`：指向下一个结点的指针。

因此，函数 `void InitPolylist(Polylist *L)` 的实现可以通过以下代码完成：

void InitPolylist(Polylist *L) {
    L->head = L->tail = (PolyNode *) malloc(sizeof(PolyNode)); // 创建头结点
    L->head->next = NULL; // 头结点的指针域置为 NULL
    L->len = 0; // 链表长度初始化为 0
}

这样，当我们需要使用一个多项式链表时，就可以先调用该函数进行初始化，然后再进行其他操作，如插入结点、删除结点、遍历链表等。

#include <stdio.h> #include <malloc.h> #include <math.h> typedef struct Polynode { double coef; int exp; struct Polynode *next; }Polynode,* Polylist; Polylist H=NULL;/*一元多项式头指针的全局变量*/ /*单链表模块*/ void InitPolylist(Polylist *L); Polylist CreatePolylist(); /*输入多项式的系数和指数,用尾插法建立一元多项式的链表*/ int LengthPolylist(Polylist L); void OutputPolylist(Polylist L); Polylist AddPolylist();/*创建两个多项式并相加，完成后显示序列*/ void ComputePolylist(Polylist L);/*计算多项式在x=%d的值*/ void DestroyPolylist(Polylist L); /*注解1：形式参数Polylist L是链表的头指针*/ /*主函数模块*/ int main() { H=AddPolylist(); ComputePolylist(H); OutputPolylist(H); DestroyPolylist(H); return 0; } /* 请在这里填写答案 */ /*单链表模块*/ void InitPolylist(Polylist *L) { } Polylist CreatePolylist()/*输入多项式的系数和指数,用尾插法建立一元多项式的链表*/ { } int LengthPolylist(Polylist L) { } void OutputPolylist(Polylist L) { } Polylist AddPolylist()/*创建两个多项式并相加，完成后显示序列*/ { } void ComputePolylist(Polylist L)/*计算多项式在x=%d的值*/ { } void DestroyPolylist(Polylist L) { }补全代码

/*单链表模块*/

/*初始化链表*/
void InitPolylist(Polylist *L) {
*L = NULL;
}

/*创建一元多项式的链表*/
Polylist CreatePolylist() {
Polylist L, p, q;
int n, i;
double coef;
int exp;

InitPolylist(&L);
printf("请依次输入多项式的项数、系数和指数：\n");
scanf("%d", &n);

for (i = 0; i < n; i++) {
scanf("%lf%d", &coef, &exp);
p = (Polylist)malloc(sizeof(Polynode));
p->coef = coef;
p->exp = exp;
p->next = NULL;

if (L == NULL) {
L = p;
} else {
q = L;
while (q->next != NULL) {
q = q->next;
}
q->next = p;
}
}
return L;
}

/*计算链表的长度*/
int LengthPolylist(Polylist L) {
int len = 0;
Polylist p = L;
while (p != NULL) {
len++;
p = p->next;
}
return len;
}

/*输出链表*/
void OutputPolylist(Polylist L) {
Polylist p = L;
if (p == NULL) {
printf("多项式为空！\n");
} else {
printf("多项式的各项系数和指数分别为：\n");
while (p != NULL) {
printf("%.2lfX^%d ", p->coef, p->exp);
p = p->next;
}
printf("\n");
}
}

/*创建两个多项式并相加，完成后返回相加后的链表*/
Polylist AddPolylist() {
Polylist L1, L2, L3, p1, p2, p3, q;
InitPolylist(&L1);
InitPolylist(&L2);
InitPolylist(&L3);

printf("请输入第1个多项式：\n");
L1 = CreatePolylist();
printf("请输入第2个多项式：\n");
L2 = CreatePolylist();

p1 = L1;
p2 = L2;
p3 = L3;

while (p1 != NULL && p2 != NULL) {
q = (Polylist)malloc(sizeof(Polynode));
if (p1->exp == p2->exp) {
q->coef = p1->coef + p2->coef;
q->exp = p1->exp;
p1 = p1->next;
p2 = p2->next;
} else if (p1->exp > p2->exp) {
q->coef = p1->coef;
q->exp = p1->exp;
p1 = p1->next;
} else {
q->coef = p2->coef;
q->exp = p2->exp;
p2 = p2->next;
}
q->next = NULL;
p3->next = q;
p3 = q;
}

while (p1 != NULL) {
q = (Polylist)malloc(sizeof(Polynode));
q->coef = p1->coef;
q->exp = p1->exp;
q->next = NULL;
p3->next = q;
p3 = q;
p1 = p1->next;
}

while (p2 != NULL) {
q = (Polylist)malloc(sizeof(Polynode));
q->coef = p2->coef;
q->exp = p2->exp;
q->next = NULL;
p3->next = q;
p3 = q;
p2 = p2->next;
}

return L3;
}

/*计算多项式在x=%d的值*/
void ComputePolylist(Polylist L) {
int x;
double result = 0.0;
printf("请输入x的值：\n");
scanf("%d", &x);

Polylist p = L;
while (p != NULL) {
result += p->coef * pow(x, p->exp);
p = p->next;
}
printf("多项式在x=%d的值为：%.2lf\n", x, result);
}

/*销毁链表*/
void DestroyPolylist(Polylist L) {
Polylist p = L, q;
while (p != NULL) {
q = p->next;
free(p);
p = q;
}
}