一个菜鸟的白痴问题。单链表

各位同为菜鸟的同学好。数据结构的作业还是要自己做的。如果不会可以像本人一样求助。但是千万不要抄袭代码。因为抄袭不会帮助你提高。而且LZ的这段代码也是作业要交的。雷同就不好了。谢谢合作。
一元多项式相加。其实差不多就是单链表的合并。
编译通过。但是运行出错。
求高手解释。
#include <iostream>

using namespace std;

typedef struct LNode
{
    int CCs;
    int exp;
    struct LNode *next;
}LNode, *Multinomial;

void CreateMultinomial(Multinomial M)
{
    //创建链表
    M = (Multinomial)malloc(sizeof(LNode));
    M->next = NULL;
    Multinomial p;
    int i;
    cout << "请输入多项式的项数:\n";
    cin >> i;
    cout << "请依次输入多项式的系数和指数:\n";
    for (; i>0; i--)
    {
        p = (Multinomial)malloc(sizeof(LNode));
        cin >> p->CCs >> p->exp;
        p->next = M->next;
        M->next = p;
    }
}

void MergepMultinomial(Multinomial Ma, Multinomial Mb, Multinomial Mc)
{
    //合并多项式
    Multinomial pa = Ma->next,    //报错这个指令引用的内存不能为"read".
        pb = Mb->next, pc, tmpM;
        Mc = (Multinomial)malloc(sizeof(LNode));
        Mc->next = NULL;
    int tmp;
    while (pa && pb)
    {
        pc = (Multinomial)malloc(sizeof(LNode));
        if (pa->exp == pb->exp)
        {
            tmp = pa->CCs + pb->CCs;
            if (tmp)
            {
                pc->CCs = tmp;
                pc->exp = pa->exp;
                pc->next = Mc->next;
                Mc->next = pc;
                pa = pa->next;
                pb = pb->next;
            }
        }
        else if (pa->exp < pb->exp)
        {
            pc->CCs = pa->CCs;
            pc->exp = pa->exp;
            pc->next = Mc->next;
            Mc->next = pc;
            pa = pa->next;
        }
        else
        {
            pc->CCs = pb->CCs;
            pc->exp = pb->exp;
            pc->next = Mc->next;
            Mc->next = pc;
            pb = pb->next;
        }
    }
    pc = (Multinomial)malloc(sizeof(LNode));
    pc = tmpM = pa ? pa : pb;
    while (pc->next)
        pc = pc->next;
    pc->next = Mc->next;
    Mc->next = tmpM;
}

void OutPutMultinomial(Multinomial M)
{
    //输出多项式
    Multinomial p = M->next;
    cout << "多项式为:\n";
    while (p->next)
    {
        if (p->next->CCs > 0)
            cout << p->CCs << "X^" << p->exp << "+";
        else
            cout << p->CCs << "X^" << p->exp;
        p = p->next;
    }
    cout << p->CCs << "X^" << p->exp << endl;
}

int main()
{
    Multinomial Ma, Mb, Mc;
    CreateMultinomial(Ma);
    CreateMultinomial(Mb);
    MergepMultinomial(Ma, Mb, Mc);
    OutPutMultinomial(Mc);
    return 0;
}
很抱歉本人可用分为0没办法给各位加分。。希望各位高手体谅一下。。。

[ 本帖最后由 Vi_No 于 2010-3-27 01:06 编辑 ]