#include"stdio.h"#include"stdlib.h"#include"conio.h"typedef struct Item{double coef;//系数int expn;//指数struct Item *next;}Item,*Polyn;#define CreateItem(p) p=(Item *)malloc(sizeof(Item));#define DeleteItem(p) free((void *)p);/************************************************************/ /* 判断选择函数 *//************************************************************/ int Select(char *str){ char ch;printf("%s\n",str);printf("Input Y or N:");do{ ch=getch();}while(ch!='Y'&&ch!='y'&&ch!='N'&&ch!='n');printf("\n");if(ch=='Y'||ch=='y') return(1);else return(0);}/************************************************************/ /* 插入位置定位函数 *//**************************************************************/ int InsertLocate(Polyn h,int expn,Item **p){ Item *pre,*q;pre=h;q=h->next;while(q&&q->expn<expn){ pre=q;q=q->next;}if(!q){ *p=pre;return(1);}else if(q->expn==expn){ *p=q;return(0);}else{ *p=pre;return(-1);}}/************************************************************/ /* 插入结点函数 *//************************************************************/ void insert(Item *pre,Item *p){p->next=pre->next;pre->next=p;}/************************************************************/ /* 输入多项式 */ /************************************************************/ Polyn Input(void){double coef;int expn,flag;Item *h,*p,*q,*pp;CreateItem(h);//产生头结点h->next=NULL;printf("input coef and expn(if end ,expn=-1)\n");while(1){scanf("%lf%d",&coef,&expn); //输入多项式的系数和指数if(expn==-1) break; //若指数为－，表示输入结束if(InsertLocate(h,expn,&pp))//返回值非表示插入新结点{ CreateItem(p);p->coef=coef;p->expn=expn;insert(pp,p);}else if(Select("has the same expn,Replace older value?")) pp->coef=coef; //指数相同，替换系数}return h;}/************************************************************/ /* 撤消多项式 */ /************************************************************/ void Destroy(Polyn h){Item *p=h,*q;while(p!=NULL){q=p;p=p->next;DeleteItem(q);}}/************************************************************/ /* 输出多项式 */ /************************************************************/ void Output(Polyn h,char *title){int flag=1;Item *p=h->next;printf("%s=",title);while(p){ if(flag) //表示是否是多项式的第一项{ flag=0;if(p->expn==0) printf("%.2lf",p->coef);else printf("%.2lfx^%d",p->coef,p->expn);}else{ if(p->coef>0) printf("+");if(p->expn==0) printf("%.2lf",p->coef);else printf("%.2lfx^%d",p->coef,p->expn);}p=p->next;}printf("\n");}/************************************************************//* 判断两个多项式项的关系 *//************************************************************/int ItemComp(Item x,Item y){ if(x.expn<y.expn)return(-1);else if(x.expn==y.expn)return(0);else return(1);}/************************************************************//* 两多项式多项式相加 *//************************************************************/Polyn AddPolyn(Polyn h1,Polyn h2){Item *head,*last,*pa=h1->next,*pb=h2->next,*s;CreateItem(head);head->next=NULL;last=head;while(pa&&pb){CreateItem(s);last->next=s;last=s;switch (ItemComp(*pa,*pb)){case -1:last->coef=pa->coef;last->expn=pa->expn;pa=pa->next;break;case 0:last->coef=pa->coef+pb->coef;last->expn=pa->expn;pa=pa->next;pb=pb->next;break;case 1:last->coef=pb->coef;last->expn=pb->expn;pb=pb->next;break;}}if(pa){while(pa){/*把剩余节点插入*/CreateItem(s);last->next=s;last=s;last->coef=pa->coef;last->expn=pa->expn;pa=pa->next;}} if(pb){while(pb){/*把剩余节点插入*/CreateItem(s);last->next=s;last=s;last->coef=pb->coef;last->expn=pb->expn;pb=pb->next;}} last->next=NULL;return head;}/************************************************************//* 两多项式多项式相减 *//************************************************************/Polyn SubtractPolyn(Polyn h1,Polyn h2){ Item *head,*last,*pa=h1->next,*pb=h2->next,*s;CreateItem(head);head->next=NULL;last=head;while(pa&&pb){CreateItem(s);last->next=s;last=s;switch (ItemComp(*pa,*pb)){case -1:last->coef=pa->coef;last->expn=pa->expn;pa=pa->next;break;case 0:last->coef=pa->coef-pb->coef;last->expn=pa->expn;pa=pa->next;pb=pb->next;break;case 1:last->coef=-(pb->coef);last->expn=pb->expn;pb=pb->next;break;}}if(pa){while(pa){/*把剩余节点插入*/CreateItem(s);last->next=s;last=s;last->coef=pa->coef;last->expn=pa->expn;pa=pa->next;}} if(pb){while(pb){/*把剩余节点插入*/CreateItem(s);last->next=s;last=s;last->coef=-(pb->coef);last->expn=pb->expn;pb=pb->next;}}last->next=NULL;return head;}/************************************************************//* 两多项式多项式相乘 *//************************************************************/Polyn MultPolyn(Polyn h1,Polyn h2) //两个多项式相乘{ int item,expn;Item *head,*pa,*pb=h2->next,*s,*pp;double coef;CreateItem(head);head->next=NULL;while(pb){pa=h1->next;while(pa){expn=pa->expn+pb->expn;coef=pa->coef*pb->coef;if(InsertLocate(head,expn,&pp)){CreateItem(s);s->coef=coef;s->expn=expn;insert(pp,s);}elsepp->coef=pp->coef+pa->coef;pa=pa->next;}pb=pb->next;}return head;}/************************************************************//* 菜单选择 *//************************************************************/int menu(void){ int num;system("cls");printf("%20c1--create P(x)\n",' ');printf("%20c2--create Q(x)\n",' ');printf("%20c3--p(x)+Q(x)\n",' ');printf("%20c4--P(x)-Q(x)\n",' ');printf("%20c5--p(x)*Q(x)\n",' ');printf("%20c6--print P(x)\n",' ');printf("%20c7--print Q(x)\n",' ');printf("%20c8--print P(x)+Q(x)\n",' ');printf("%20c9--print P(x)-Q(x)\n",' ');printf("%20c10--print P(x)*Q(x)\n",' ');printf("%20c11--Quit\n",' ');printf(" please select 1,2,3,4,5,6,7,8,9,10,11:");do{scanf("%d",&num);}while(num<1 || num>11);return(num);}/************************************************************//* 判断多项式是否存在 *//************************************************************/int PolynNotEmpty(Polyn h,char *p){ if(h==NULL){ printf("%s is not exist!\n",p);getchar();return(0);}else return(1);}/************************************************************//* 主函数 *//************************************************************/ void main(){ int num;Polyn h1=NULL; //指向p(x) 指针Polyn h2=NULL; //指向Q(x) 指针Polyn h3=NULL; //指向P(x)+Q(x) 指针Polyn h4=NULL; //指向P(x)-Q(x) 指针Polyn h5=NULL; //指向P(x)*Q(x) 指针while(1){ num=menu();getchar();switch(num){case 1: //输入第一个多项式，若多项式存在，首先撤消然后再输入if(h1!=NULL){ if(Select("P(x) is not Empty,Create P(x) again?")) { Destroy(h1);h1=Input();}}else h1=Input();break;case 2: //输入第二个多项式，若多项式存在，首先撤消然后再输入if(h2!=NULL){ if(Select("Q(x) is not Empty,Create Q(x) again?")) { Destroy(h2);h2=Input();}}else h2=Input();break;case 3: //两多项式相加if(PolynNotEmpty(h1,"p(x)")&&PolynNotEmpty(h2,"Q(X)"))//判断俩多项式都非空 {h3=AddPolyn(h1,h2);Output(h3,"P(x)+Q(X)");printf("P(x)+Q(x) has finished!\n");getchar();}break;case 4: //两多项式相减if(PolynNotEmpty(h1,"p(x)")&&PolynNotEmpty(h2,"Q(X)")){ h4=SubtractPolyn(h1,h2);Output(h4,"P(x)-Q(x)");printf("P(x)-Q(x) has finished!\n");getchar();}break;case 5: //两多项式相乘if(PolynNotEmpty(h1,"p(x)")&&PolynNotEmpty(h2,"Q(X)")) { h5=MultPolyn(h1,h2);Output(h5,"P(x)*Q(x)");printf("P(x)*Q(x) has finished!\n");getchar();}break;case 6: //显示第一个多项式if(PolynNotEmpty(h1,"p(x)")){ Output(h1,"P(x)");getchar();}break;case 7: //显示第二个多项式if(PolynNotEmpty(h2,"Q(x)")){ Output(h2,"Q(x)");getchar();}break;case 8: //显示相加结果多项式if(PolynNotEmpty(h3,"P(x)+Q(x)")){ Output(h3,"P(x)+Q(x)");getchar();}break;case 9: //显示相减结果多项式if(PolynNotEmpty(h4,"P(x)-Q(x)")){ Output(h4,"P(x)-Q(x)");getchar();}break;case 10: //显示相乘结果多项式if(PolynNotEmpty(h5,"P(x)*Q(x)")){ Output(h5,"P(x)*Q(x)");getchar();}break;case 11: //结束程序运行。