多项式加法的链表实现 

  1 /*
  2  encoding:GBK
  3  time:
  4  environment:Dev-C++ 5.11 
  5 */
  6 #include<iostream>
  7 #include<math.h>
  8 using namespace std;
  9 
 10 #define maxn 200
 11 bool sgn(float a){return fabs(a)<1e-8;}
 12 typedef struct{//存放多项式的二元组,将二元组数组起别名 
 13     float coef;
 14     int exp;
 15 }PolyArray[maxn];
 16 
 17 struct PolyNode{//结点的定义 
 18     float coef;
 19     int exp ;
 20     PolyNode* next;
 21 };
 22 
 23 class Poly{//多项式类 
 24     private:
 25         PolyNode* Head;
 26     public:
 27         Poly();//构造函数
 28         ~Poly();//析构函数，释放多项式 
 29         void PolyDisplay();//显示多项式 
 30         void CreatePoly(PolyArray a,int n);//创建多项式链表
 31         void PolySort();//有序表排序
 32         void PolyAdd(Poly LB);//多项式相加 
 33 };
 34 
 35 
 36 void Poly::CreatePoly(PolyArray a,int n)//二元表以及二元表的大小 
 37 {
 38     PolyNode *s,*r;
 39     int i;
 40     r = Head;
 41     for(int i = 0; i < n; i ++)    
 42     {
 43         s = new PolyNode;
 44         s->coef = a[i].coef;
 45         s->exp = a[i].exp;
 46         s->next = NULL;
 47         r->next = s;
 48         r = s;
 49     }
 50 }
 51 void Poly::PolySort()//表的排序 
 52 {
 53     PolyNode *p,*q,*r;
 54     p = Head->next; 
 55     if(p!=NULL)
 56     {
 57         r = p->next;
 58         p->next = NULL;
 59         p = r;
 60         while(p!=NULL)
 61         {
 62             r = p->next;
 63             q = Head;
 64             while((q->next!=NULL) && (q->next->exp < p->exp))
 65                 q = q->next;
 66                 
 67                 p->next = q->next;
 68                 q->next = p;
 69                 p = r;
 70         }
 71     }
 72 }
 73 //errors exist 
 74 void Poly::PolyAdd(Poly LB)
 75 {
 76     float sum;
 77     PolyNode *pa,*pb,*qa,*qb;
 78     pa = Head;//pa pb 指向两条链的头结点。qa qb 指向了两条链的首元 
 79     qa = pa->next;
 80     pb = LB.Head;
 81     qb = pb->next;
 82     while(qa!=NULL && qb!=NULL)//分成三种情况操作 
 83     {
 84         if(qa->exp < qb->exp)
 85         {
 86             pa = qa;
 87             qa = qa->next;
 88         }
 89         else if(qa->exp >qb->exp)
 90         {
 91             pb->next = qb->next;
 92             qb->next = qa;
 93             pa->next = qb;
 94             pa = qb;
 95             qb = pb->next;
 96         }
 97         else
 98         {
 99             sum = qa->coef+qb->coef;
100             if(sum == 0)//系数为0的时候删除结点 ,浮点数不会严格等于零，所以需要判断 
101             {
102                 pa->next = qa->next;
103                 delete qa;
104                 qa = qa->next;
105                 pb->next = qb->next;
106                 delete qb;
107                 qb = pb->next;
108             }
109             else
110             {
111                 qa->coef = sum;
112                 pa = qa; qa = qa->next;
113                 pb->next = qb->next;
114                 delete qb;
115                 qb = pb->next;
116             }
117         }
118     }
119     if(qb!=NULL)
120     {
121         pa->next = qb;
122     }
123 }
124 void Poly::PolyDisplay()
125 {
126     PolyNode* q = Head;
127     q = q->next;
128     while(q!=NULL)
129     {
130         if(q->coef!=0)
131         {
132             cout<<"("<<q->coef<<","<<q->exp<<") "; 
133         }
134         q=q->next;    
135     }
136     cout<<endl; 
137 }
138 Poly::Poly(){Head = new PolyNode;}
139 Poly::~Poly(){Head = NULL;}
140 int main()
141 {
142     Poly LA,LB;
143     PolyArray a = {{7.0,0},{3.0,1},{9.0,8},{5.0,16}};
144     PolyArray b = {{8.0,1},{22,7},{-9.0,8}};
145     
146 //    PolyArray a1 = {{3.0,1},{7.0,0},{5.0,16},{9.0,8}};
147     LA.CreatePoly(a,4);
148     LB.CreatePoly(b,3);
149     LA.PolyDisplay();
150     LB.PolyDisplay();
151     LA.PolySort();
152     LB.PolySort();
153     //展示合并之前的多项式 
154     LA.PolyDisplay();
155     LB.PolyDisplay();
156     
157     //多项式加法 
158     LA.PolyAdd(LB);
159     //展示合并后的多项式 
160     LA.PolyDisplay(); 
161 }

 

posted @ 2020-05-07 17:11  WA自动机~  阅读(277)  评论(0)  编辑  收藏  举报