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 }
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