C++数据结构实现多项式相乘，小弟我代码实在不知道是有关问题出在哪了
C++数据结构实现多项式相乘，，我代码实在不知道是问题出在哪了
------解决思路----------------------
返回类型应该是Polynomial，不管怎么样也不应该返回栈上对象的引用
------解决思路----------------------
遍历单链表有点奇怪， tail这个结点不需要了吗？
里面代码比较多，建议term提供operator<<, 至于term之间的符号输出由Poly的out控制，不然这样看起来太累
------解决思路----------------------
里面的逻辑确实有点奇怪，这个链表的tail就是用来插入的吧，里面的else if判断确实没有必要，遍历一次链接就好了
------解决思路----------------------
崩溃的时候在弹出的对话框按相应按钮进入调试，按Alt+7键查看Call Stack里面从上到下列出的对应从里层到外层的函数调用历史。双击某一行可将光标定位到此次调用的源代码或汇编指令处，看不懂时双击下一行，直到能看懂为止。
仅供参考
#include <iostream>
#include<stdlib.h>
using namespace std;
class Term//单循环链表的结点类
{
public:Term(int c, int e);//结点的构造函数
Term(int c, int e, Term* nxt);
private:int exp;
int coef;
Term* link;
friend class Polynomial;
};
Term::Term(int c, int e)
{
link = 0;
exp = e;
coef = c;
}
Term::Term(int c, int e, Term* nxt)
{
link = nxt;
exp = e;
coef = c;
}
class Polynomial//多项式的类
{
public:Polynomial();
~Polynomial();
void Input();
void Output();
void addTerm(int c,int e);
Polynomial& operator * (Polynomial& bh);
void operator =(Polynomial& ah);
private:Term* Head;
Term* Tail;
};
Polynomial:: Polynomial()//构造一个头指针，一个尾指针
{
Head = NULL;
Tail = Head;
}
Polynomial::~Polynomial(){}
void Polynomial::Input()//输入多项式
{
int c, e;
Term* p=NULL;//为什么定义的是Term类的指针而不是Polynomial类的
cout << "请输入coef,exp(以空格隔开，0 0结束)：" << endl;
for (;;){
cin >> c >> e;
if (c ==0) break;
else{
if (Head==NULL){
p = new Term(c, e, NULL);
Head = p;
Tail = p;
}
else if(Head!=NULL) {
p->link = new Term(c, e, NULL);
p = p->link;
Tail = p;
}
}
}
}
void Polynomial::Output()//显示多项式
{
Term* p =Head;
cout << "此多项式为：";
while(p!=Tail)//p!=Tail时，让其一直循环输出
{
if (p == Head)
{
if (p->coef == 1){
if (p->exp == 0){
cout << p->coef;
}
else if (p->exp == 1){
cout << "X";
}
else {
cout << "X^" << p->exp;
}
}
else if (p->coef == -1){
if (p->exp == 0){
cout << p->coef;
}
else if (p->exp == 1){
cout << "-X";
}
else {
cout << "-X^" << p->exp;
}
}
else{
if (p->exp == 0){
cout << p->coef;
}
else if (p->exp == 1){
cout << p->coef<<"X";
}
else {
cout << p->coef<<"X^" << p->exp;
}
}
p = p->link;
}
else
{
if (p->exp == 0){
if (p->coef > 0){
cout << "+" << p->coef;
}
else if (p->coef < 0){
cout << p->coef;
}
}
else if (p->exp == 1){
if (p->coef>0){
if (p->coef == 1){
cout << "+" <<"X";
}
else
cout << "+" << p->coef << "X";
}
else if (p->coef < 0){
if (p->coef == -1){
cout <<"-X";
}
else
cout << p->coef << "X";
}
}
else {
if (p->coef>0){
if (p->coef == 1){
cout << "+X^" << p->exp;
}
else
cout << "+" << p->coef << "X^" << p->exp;
}
else if (p->coef < 0){
if (p->coef == -1){
cout << "-X^" << p->exp;
}
cout << p->coef << "X^" << p->exp;
}
}
p = p->link;
}
}
if (p->exp == 0){//当p为Tail时（运行的时候问题也就是出在这里了）
if (p->coef > 0){
cout << "+" << p->coef;
}
else if (p->coef < 0){
cout << p->coef;
}
}
else if (p->exp == 1){
if (p->coef>0){
if (p->coef == 1){
cout << "+" << "X";
}
else
cout << "+" << p->coef << "X";
}
else if (p->coef < 0){
if (p->coef == -1){
cout << "-X";
}
else
cout << p->coef << "X";
}
}
else {
if (p->coef>0){
if (p->coef == 1){
cout << "+X^" << p->exp;
}
else
cout << "+" << p->coef << "X^" << p->exp;
}
else if (p->coef < 0){
if (p->coef == -1){
cout << "-X^" << p->exp;
}
cout << p->coef << "X^" << p->exp;
}
}
cout << endl;
}
void Polynomial::addTerm(int c, int e)//实现对新插入的结点的排序
{
Term* p;
Term* q=Head;
if (Head == NULL){//空的时候
Head = new Term(c, e, NULL);
p = Head;
Tail = Head;
}
else if (Head ==Tail&&Head!=NULL) {//只有一个的时候
p = new Term(c, e, NULL);
if (p->exp>Head->exp){
p->link=Head;
Tail = Head;
Head = p;
//Tail->link = p;
}
else if (p->exp == Head->exp){
Head->coef = Head->coef + p->coef;
delete p;
}
else if (p->exp < Head->exp){
Head->link = p;
Tail = p;
}
}
else if (Head !=Tail){//有多个的时候
p = new Term(c, e, NULL);
if (p->exp>Head->exp){
p->link = Head;
Head = p;
}
else if (p->exp == Head->exp){
Head->coef = Head->coef + p->coef;
delete p;
}
else if (p->exp < Tail->exp){
Tail->link = p;
Tail = p;
}
else if (p->exp == Tail->exp){
Tail->coef = Tail->coef + p->coef;
delete p;
}
else if (p->exp<Head->exp&&p->exp>Tail->exp){
q = Head;
if (q->exp>p->exp&&q->link->exp <= p->exp){
if (q->link->exp<p->exp){
q->link = p;
p->link = q->link;
}
else if (q->link->exp == p->exp){
q->link->coef = q->link->coef + p->coef;
delete p;
}
}
do
{
q = q->link;
}
while (q->exp>p->exp&&q->link->exp<=p->exp);
if (q->link->exp<p->exp){
q->link = p;
p->link = q->link;
}
else if (q->link->exp == p->exp){
q->link->coef = q->link->coef + p->coef;
delete p;
}
}
}
}
Polynomial& Polynomial::operator * (Polynomial& bh){//重载*
Polynomial ans;
Term* p=Head;
Term* q=0;
//Tail->link = Head;
for (p = Head; p!=Tail; p = p->link){
for (q = bh.Head; q !=bh.Tail; q = q->link){
ans.addTerm(p->coef*q->coef,p->exp+q->exp);//两个for嵌套循环，实现两个多项式的相乘，并且边乘边排序
}
ans.addTerm(p->coef*q->coef, p->exp + q->exp);
}
if (p == Tail){
for (q = bh.Head; q != bh.Tail; q = q->link){
ans.addTerm(p->coef*q->coef, p->exp + q->exp);
}
ans.addTerm(p->coef*q->coef, p->exp + q->exp);
}
return ans;//最后将乘好的结果返回（降幂）
}
void Polynomial::operator =(Polynomial& ah){//重载=
Head = ah.Head;
Tail = ah.Tail;
}
int main()
{
Polynomial ah,bh,ch;
ah.Input();
ah.Output();
bh.Input();
bh.Output();
ch = ah*bh;
ch.Output();
return 0;
}
------解决思路----------------------
Polynomial& Polynomial::operator * (Polynomial& bh){//重载*
Polynomial ans;
...
return ans;//最后将乘好的结果返回（降幂）
}
返回类型应该是Polynomial，不管怎么样也不应该返回栈上对象的引用
------解决思路----------------------
while(p!=Tail)//p!=Tail时，让其一直循环输出
遍历单链表有点奇怪， tail这个结点不需要了吗？
里面代码比较多，建议term提供operator<<, 至于term之间的符号输出由Poly的out控制，不然这样看起来太累
------解决思路----------------------
void Polynomial::addTerm(int c, int e)//实现对新插入的结点的排序
里面的逻辑确实有点奇怪，这个链表的tail就是用来插入的吧，里面的else if判断确实没有必要，遍历一次链接就好了
------解决思路----------------------
崩溃的时候在弹出的对话框按相应按钮进入调试，按Alt+7键查看Call Stack里面从上到下列出的对应从里层到外层的函数调用历史。双击某一行可将光标定位到此次调用的源代码或汇编指令处，看不懂时双击下一行，直到能看懂为止。
仅供参考
//带表头结点的单向链表
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <time.h>
struct NODE {
int data;
struct NODE *next;
} H,*head,*p,*q,*s1,*s2,*s3,*s4,*s;
int i,j,k,n,t,m;
int main() {
srand(time(NULL));
//填写头节点数据
H.data=-1;
H.next=NULL;
head=&H;
//创建10个节点的单链表
p=head;
for (i=0;i<10;i++) {
q=(struct NODE *)malloc(sizeof(struct NODE));
if (NULL==q) return 1;
q->data=rand()%100;//填写0..99的随机值
q->next=NULL;
p->next=q;
p=q;
}
//输出整个单链表
s=head->next;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
//将值为5的结点插入到单链表的第k个结点前
k=3;
n=0;
p=head;
while (1) {
if (NULL==p) {
break;
}
n++;
if (k==n) {
q=(struct NODE *)malloc(sizeof(struct NODE));
if (NULL==q) return 1;
q->data=5;
q->next=p->next;
p->next=q;
break;
}
p=p->next;
}
//输出整个单链表
s=head->next;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
//删除第k个节点
k=5;
n=0;
p=head;
while (1) {
if (NULL==p) {
break;
}
n++;
if (k==n) {
q=p->next;
if (q) {
p->next=q->next;
free(q);
}
break;
}
p=p->next;
}
//输出整个单链表
s=head->next;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
//从小到大排序
for (p=head;p!=NULL && p->next!=NULL;p=p->next) {
for (q=p->next;q!=NULL && q->next!=NULL;q=q->next) {
if (p->next->data > q->next->data) {
//交换data
// printf("swap %02d %02d\n",p->next->data,q->next->data);
// t=p->next->data;p->next->data=q->next->data;q->next->data=t;
//或者
//交换next
// printf("swap %02d %02d\n",p->next->data,q->next->data);
s1=p->next;
s2=p->next->next;
s3=q->next;
s4=q->next->next;
if (s2!=s3) {
p->next=s3;
s3->next=s2;
q->next=s1;
s1->next=s4;
} else {
p->next=s3;
s3->next=s1;
q=s3;
s1->next=s4;
}
//输出整个单链表
// s=head->next;
// while (1) {
// if (NULL==s) {
// printf("\n");
// break;
// }
// printf("%02d->",s->data);
// s=s->next;
// }
// getchar();
}
}
}
//输出整个单链表
s=head->next;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
//将单链表中前 m 个结点和后 n 个结点进行互换,m+n为链表总长10
m=4;
n=6;
k=0;
p=head;
while (1) {
if (NULL==p) {
break;
}
k++;
if (m+1==k) {
q=p;
}
s=p;
p=p->next;
}
s1=head->next;
head->next=q->next;
s->next=s1;
q->next=NULL;
//输出整个单链表
s=head->next;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
//释放所有节点
p=head->next;
while (1) {
if (NULL==p) {
break;
}
q=p->next;
free(p);
p=q;
}
return 0;
}
//18->94->58->17->27->20->43->57->75->78->
//18->94->05->58->17->27->20->43->57->75->78->
//18->94->05->58->27->20->43->57->75->78->
//05->18->20->27->43->57->58->75->78->94->
//43->57->58->75->78->94->05->18->20->27->
//