void SortPolyn(polynomail *p) {
Link *p1, *p2; //采用直接插入排序
for (p1 = p->head->next; p1; p1 = p1->next) {
for (p2 = p->head->next; p2 != p1; p2 = p2->next) {
if (p2->data->expn == p1->data->expn) { //若后边待排序的节点的指数跟前面已排序
Link *pri; //节点的指数相同，则应该合并两项，即删除后者，并入前者
p2->data->coef += p1->data->coef;
pri = PriorPos(*p, p1);
DelFirst(pri, &p1);
FreeNode(p1);
--p->len;
if (fabs(p2->data->coef) < 1e-6) { //如果合并后系数为0，那也要把这个节点删除
pri = PriorPos(*p, p2);
DelFirst(pri, &p2);
FreeNode(p2);
--p->len;
}
p1 = pri;
break;
}
else if (p1->data->expn < p2->data->expn) {
Link *pri1, *pri2;
pri1 = PriorPos(*p, p1);
DelFirst(pri1, &p1);
pri2 = PriorPos(*p, p2);
InsFirst(pri2, p1);
p1 = pri1;
break;
}
}
}
p->tail = GetLast(*p);
}
main()
{
DList *plist = NULL;
PNode p = NULL;
plist = InitList();
p = InsFirst(plist,MakeNode(1));
InsBefore(plist,p,MakeNode(2));
InsAfter(plist,p,MakeNode(3));
printf("p前驱位置的值为%d\n",GetItem(GetPrevious(p)));
printf("p位置的值为%d\n",GetItem(p));
printf("p后继位置的值为%d\n",GetItem(GetNext(p)));
printf("遍历输出各节点数据项:\n");
ListTraverse(plist,print);
printf("除了头节点该链表共有%d个节点\n",GetSize(plist));
FreeNode(DelFirst(plist));
printf("删除第一个节点后重新遍历输出为:\n");
ListTraverse(plist,print);
printf("除了头节点该链表共有%d个节点\n",GetSize(plist));
DestroyList(plist);
printf("链表已被销毁\n");
}
/**
* 算法2.20，在带头结点的单链线性表L的第i个元素之前插入元素e
*/
Status ListInsert(LinkList &L, int i, ElemType e)
{
Link h, s;
if (!LocatePos(L, i-1, h))
return ERROR;
if (!MakeNode(s, e))
return ERROR;
if (h == L.tail)
L.tail = s; // 修改尾指针
InsFirst(h, s); //对于从第不个结点开始的链表，第i-1个结点是它的头结点
L.len++;
return OK;
}
Status InsBefore(LinkList *linklist, Link **p, Link *h) {
Link *t;
if (!linklist || linklist->len == 0 || !h)
return ERROR;
for (t = linklist->head; t->next&&t->next != *p; t = t->next);
if (!t->next) // p不是链表中的节点
return ERROR;
if (InsFirst(t, h) == ERROR)
return ERROR;
++linklist->len;
*p = h;
return OK;
}
Status LinkListInsert(LinkList *linklist, int position, ElemType e) {
Link *t; //只能插入到[0,len)之间的位置，不会改变尾结点
Link *newnode;
if (!linklist)
return ERROR;
if (position != 0) {
if (LocatePos(*linklist, position - 1, &t) == ERROR)return ERROR;
}
else {
t = linklist->head;
}
if (MakeNode(&newnode, e) == ERROR)return ERROR;
if (InsFirst(t, newnode) == ERROR)return ERROR;
linklist->len++;
return OK;
}
Link *sub_MultiplyPolyn(Link *p, polynomail *pb) {
Link *pt, *head = NULL, *newnode = NULL;
Link *t;
ElemType e = NULL;
double coef, coef_ori = p->data->coef;
int expn, expn_ori = p->data->expn;
for (pt = pb->head->next; pt; pt = pt->next) { //遍历pb的每个结点，分别于p相乘
coef = coef_ori; //得到的新数据包装成结点并链成新链表
expn = expn_ori; //然后返回这一串结点的首节点地址
coef *= pt->data->coef;
expn += pt->data->expn;
if (SetPolyn(&e, coef, expn) == ERROR)return NULL; //组成数据域
if (MakeNode(&newnode, e) == ERROR)return NULL; //包装成行指针域的节点
if (pt == GetHead(*pb))head = t = newnode; //将结点插入链表
else {
if (InsFirst(t, newnode) == ERROR)return NULL;
t = t->next;
}
}
return head;
}
