用带头结点的循环链表求多项式加法，release版本下结果正确，debug版本下发生内存访问错误。个人觉得是代码有问题，调试运行后，问题出在delete(pb)，暂时注释delete后，又在Output函数内终止。看了好几遍感觉也没有逻辑问题，代码有点长，希望各位有时间能帮小弟解决一下，感激不尽！
#include<iostream>
#include<stdlib.h>
using namespace std;
typedef int ElemType;
typedef struct Lnode
{
int quo;
int deg;
struct Lnode *next;
}Lnode, *Linklist;
//逆序创建循环链表，该循环链表的头指针指向最后一个节点
void CreateList_L(Linklist &L, ElemType Q[], ElemType D[], int n)
{
L = NULL;
Linklist s;
for (int j = n - 1; j >= 0; --j)
{
s = new Lnode;
s->deg = D[j];
s->quo = Q[j];
s->next = L;
L = s;
}
s = new Lnode;//补充头结点
s->deg = 111111111;
s->quo = 11111111;
s->next = L;
L = s;
while (s->next != NULL)
{
s = s->next;
}
s->next = L;
L = s;
}
//销毁链表
void destory(Linklist &L)
{
Linklist p;
p = L->next;
while (p != L->next)
{
p = L; L = L->next; free(p);
}
}
//输出线性表
void Output(Linklist &L)
{
Linklist plist = L->next->next;
while (plist != L->next)
{
cout << plist->quo << " ";
cout << plist->deg << '\n';
plist = plist->next;
}
cout << endl;
}
//两个多项式相加
void Polyadd(Linklist &L, Linklist &P)
{
Linklist pa, pb, rc, qa, qb;
pa = L->next->next;
pb = P->next->next;
rc = L->next;
while (pa != L->next&&pb != P->next)
{
if (pa->deg<pb->deg)//pb指数大时，pb链接到rc中
{
rc->next = pb; rc = pb; pb = pb->next;
}
else
{
if (pa->deg>pb->deg)//pa指数大时，pa链接到rc中
{
rc->next = pa; rc = pa; pa = pa->next;
}
else
{
if ((pa->quo + pb->quo) != 0)//如果系数相加不为零
{
pa->quo = pa->quo + pb->quo; rc->next = pa; rc = pa; pa = pa->next; qb = pb; pb = pb->next; delete qb; qb = NULL;
}//将pa中的系数值改为pa系数+pb系数，把pa链接到rc中，rc向后移动，用qb分别把pb结点记录下来，pa，pb向后移动，再将qb删除
else//如果系数相加为零
{
qa = pa; pa = pa->next; qb = pb; pb = pb->next; delete qa; qa = NULL; delete qb; qb = NULL;
}//用qa，qb分别把pa，pb结点记录下来，pa，pb向后移动，再将qa，qb删除
}
}
}
if (pb == P->next)
{
rc->next = pa;
}
else
{
rc->next = pb; pb = P->next; P->next = L->next; L = P;
}
delete(pb);//!!!!!!!!!!!!!删去此处也不可
}
int main()
{
Linklist L, P;
int n = 4;
//ElemType Q1[]={5,9},D1[]={11,8};
ElemType Q1[] = { 5, 9, 3, 7 }, D1[] = { 11, 8, 1, 0 };
CreateList_L(L, Q1, D1, n);
cout << "多项式L的系数和相应的次数分别为：" << endl;
Output(L);
int m = 2;
ElemType Q2[] = { 9,5}, D2[] = { 8,1};
CreateList_L(P, Q2, D2, m);
cout << "多项式P的系数和相应的次数分别为：" << endl;
Output(P);
Polyadd(L, P);
cout << "多项式P+L的系数和相应的次数分别为：" << endl;
Output(L);
//destory(L);
//destory(P);
}
release下截图：
debug下截图：
