问题描述

c++ 内存问题 找了好久都不知道呢错了

#include<iostream>

using namespace std;

struct Node
{
float coef;//系数
int expn;//指数
Node* next;
};

class Ploy
{
public:
Ploy();
~Ploy();
void CreatePloy(int n);
void DispPloy();
void PloyAdd(Ploy b);
Node* GetNode()
{
return head;
}
int compare(const Node *p1,const Node *p2)
{
if(p1->expn < p2->expn)//小于
return -1;
else if(p1->expn == p2->expn)//等于
return 0;
else //大于
return 1;
}
private:
Node *head;

};

Ploy::Ploy()
{
head = new Node;
head->next = NULL;
}
Ploy::~Ploy()
{
Node *p;

while(head)
{
    p = head;
    head  = head->next;
    delete p;
}
head = NULL;
cout<<"xigou is running"<<endl;

}

void Ploy::CreatePloy(int n)
{
int i=1;
Node *p,*s;
p = head;
for (i;i<=n;i++)
{
cout<<"请输入第"<<i<<"项(系数，指数);";
s = new Node;

    cin>>s->coef;
    cin>>s->expn;
    s->next = p->next;
    p->next = s;
    p = s;
}

}

void Ploy::DispPloy()
{
Node p;
p = head;
while(p->next != NULL)
{
p = p->next;
cout<coef<<""<<"x"<<"^"<expn<<"+";
}
cout<<endl;
}

void Ploy::PloyAdd(Ploy p_b)
{
Node *pa,*pb,*psum;
Ploy p_sum;
pb = p_b.GetNode()->next;
pa = head->next;
psum = p_sum.GetNode();
//psum->next = head->next;
int sum;

while(pa && pb)
{
    switch(compare(pa,pb))
    {
    case  -1:psum->next = pa;
             psum = pa;
             pa = pa->next;
             break;
    case 0: sum  = pa->coef + pb->coef;
            pa->coef = sum;
            psum->next = pa;
            psum = pa;
            pa = pa->next;

            pb = pb->next;

            break;
    case 1:psum->next = pb;
           psum = pb;
           pb = pb->next;
           break;
    }

}
psum->next = pa?pa:pb;
p_sum.DispPloy();

}

int main()
{
Ploy p1,p2;
p1.CreatePloy(5);
p1.DispPloy();
p2.CreatePloy(5);
p2.DispPloy();
p1.PloyAdd(p2);
p1.DispPloy();
return 0;

}
这个是实现多项式加法的 但不知道呢出错了 希望各位前辈帮忙看看 报的_block_type_is_valid