课程设计报告1.需求分析【问题描述】设计一个一元稀疏多项式简单计算器.【基本要求】一元稀疏多项式基本功能包括：1)输入并建立多项式；2)输出多项式，输出形式为整数序列：n, c1, e1, c2, e2, … , c n, e n，其中n是多项式的项数，c i和e i分别是第i项的系数和指数，序列按指数降序排列；3)多项式a和b相加，建立多项式a+b；4)多项式a和b相减，建立多项式a-b；【测试数据】1)(2x+5x8-3.1x11)+(11x9-5x8+7)=(-3.1x11+11x8+2x+7)2)(-1.2x9+6x-3+4.4x2-x)-(7.8x15+4.4x2-6x-3)=(-7.8x15-1.2x9+12x-3-x)3)(x5+x4+x3+x2+x+1)-(-x4-x3)=(x5+x2+x+1)4)(x3+x)-(-x3-x)=05)(x100+x)+(x200+x100)=(x200+2x100+x)6)(x3+x2+x)+0=x3+x2+x7)互换上述测试数据中的前后两个多项式.2.概要设计ADT Polynomial{数据对象: D={a i|a i∈TermSet, i=1,2,…,m,m≥0,TermS et中的每个元素包含一个表示系数的实数和表示指数的整数}数据对象: R1={<a i,a i-1>|a i,a i-1∈D,且a i-1中的指数值小于ai中的指数,i=2,…,m}基本操作：CreatePolyn(void)Result: 指数由大到小输入m项的系数和指数,建立一元多项式pPrintPoly(LNode Head)Result: 输出一元多项式AddPoly(LNode H1,LNode H2)Condition: 一元多项式pa,pb已存在Result: 完成多项式相加运算,即pa=pa+pb,并销毁一元多项式pb.SubtractPoly(LNode H1,LNode H2)Condition: 一元多项式pa,pb已存在Result: 完成多项式相减运算,即pa=pa-pb,并销毁一元多项式pb.}ADT Polynomial3.详细设计【数据类型定义】typedef struct node{int expn,coef;struct node *next;}Nodetype,*LNode; //定义结点类型【函数原型定义】LNode CreatePolyn(void);Void PrintPoly(LNode Head);LNode AddPolyn(LNode H1,LNode H2);LNode SubPolyn(LNode H1,LNode H2);【核心算法描述】CreatePolyn()LNode CreatePolyn(void) //创建表达式{LNode Head,p,pre,pree;int x,z;Head=(LNode)malloc(sizeof(Nodetype));Head->next=NULL;printf("当你输入的系数为0时，输入将结束！\n");printf("请输入第一项系数:");scanf("%d",&x);if(x==0){p=(LNode)malloc(sizeof(LNode));p->coef=0;p->expn=0;Head->next=p;p->next=NULL;}while(x!=0){printf("请输入指数:");scanf("%d",&z);p=(LNode)malloc(sizeof(Nodetype));p->coef=x;p->expn=z;pre=Head;while(pre->next&&pre->next->expn>=z)//原有项指数大于插入项{pree=pre;pre=pre->next;}p->next=pre->next;//插入项pre->next=p;if(pre->expn==p->expn)//原有项指数等于插入项{pre->coef+=p->coef;pre->next=p->next;free(p);}if(pre->coef==0)//系数为0{pree->next=pre->next;free(pre);}printf("请输入系数:");scanf("%d",&x);}if(Head->next==NULL)//多项式空{pre=(LNode)malloc(sizeof(LNode));pre->coef=0;pre->expn=0;pre->next=Head->next;Head->next=pre;}return Head;}PrintPolyn()void PrintPolyn(LNode Head) //输出表达式{LNode pre;pre=Head->next;if(pre->expn==0)//指数为0printf("%d",pre->coef);elseprintf("%d*X(%d)",pre->coef,pre->expn);pre=pre->next;while(pre)//系数不为0{if(pre->expn==0)//指数为0{if(pre->coef>0)printf("+%d",pre->coef);else if(pre->coef<0)printf("%d",pre->coef);}else//指数不为0{if(pre->coef>0)printf("+%d*X(%d)",pre->coef,pre->expn);else if(pre->coef<0)printf("%d*X(%d)",pre->coef,pre->expn);}pre=pre->next;//遍历每一项}printf("\n");}AddPolyn()LNode AddPolyn(LNode H1,LNode H2) //表达式相加{LNode H3,p1,p2,p3,pre;//p1第一个多项式的项，pre p的前一项H3=(LNode)malloc(sizeof(LNode));H3->next=NULL; //建立一个空的多项式p1=H1->next; //第一个多项式的第一项p2=H2->next;pre=H3; //while(p1&&p2){if(p1->expn>p2->expn)//第一个多项式的项的指数大于第二个的{p3=(LNode)malloc(sizeof(LNode));p3->expn=p1->expn;p3->coef=p1->coef;p3->next=pre->next;pre->next=p3;pre=p3;p1=p1->next;}else if(p1->expn<p2->expn)//第一个多项式的项的指数小于第二个的{p3=(LNode)malloc(sizeof(LNode));p3->expn=p2->expn;p3->coef=p2->coef;p3->next=pre->next;pre->next=p3;pre=p3;p2=p2->next;else if(p1->coef+p2->coef!=0)//相加为不0，指数相同系数相加{p3=(LNode)malloc(sizeof(LNode));p3->expn=p1->expn;p3->coef=p1->coef+p2->coef;p3->next=pre->next;pre->next=p3;pre=p3;p1=p1->next;p2=p2->next;}else//相加为0{p1=p1->next;p2=p2->next;}}while(p2){p3=(LNode)malloc(sizeof(LNode));p3->expn=p2->expn;p3->coef=p2->coef;p3->next=pre->next;pre->next=p3;pre=p3;p2=p2->next;}while(p1){p3=(LNode)malloc(sizeof(LNode));p3->expn=p1->expn;p3->coef=p1->coef;p3->next=pre->next;pre->next=p3;pre=p3;p1=p1->next;}return H3;}LNode SubstractPolyn(LNode H1,LNode H2) //表达式相减{//让系数变负，代入加法LNode H3,pre;pre=H2->next;while(pre){pre->coef=-pre->coef;pre=pre->next;}H3=AddPolyn(H1,H2);pre=H2->next;while(pre){pre->coef=-pre->coef;pre=pre->next;}return H3;}【函数调用关系】main()调用CreatePoly()，PrintPoly()，AddPoly()，scanf()函数输入，printf()函数输出。
