读入合法字符

1、#include <stdio.h>#include <stdlib.h>#define OK 1;#define READ(I) while (I)=getchar()='n'); /读入合法字符typedef int status;typedef struct PolyNode float coef; int expn; struct PolyNode *next;Poly,*P_Poly;status CreatPoly(P_Poly*,int); /创建多项式链表void OutP_Poly(P_Poly); /输出多项式void AddPoly

2、(P_Poly*,P_Poly,P_Poly); /求和void DecPoly(P_Poly*,P_Poly,P_Poly); /求差void DelPoly(P_Poly*); /删除并释放多项式status main() P_Poly PolyHead26=0; char menu,name; for (;) printf ("1.建立多项式n"); printf ("2.输出多项式n"); printf ("3.求两个多项式之和(必须先创建),建立和式并输出n"); printf ("4.求两个多项式之差(必须先创建

3、),建立差式并输出n"); printf ("5.删除多项式n"); printf ("6.退出n"); printf ("请选择指令:"); READ(menu) switch (menu) case '1': int n; printf ("请输入要创建的多项式的名称（单个小写字母表示）:"); READ(name) if (NULL!=PolyHeadname-'a') printf ("此多项式已经存在!n"); break; printf (&

4、quot;请输入项数:"); scanf ("%d",&n); if(CreatPoly(&PolyHeadname-'a',n) printf ("多项式%c创建完毕!n",name); break; case '2': printf ("请输入要输出的多项式的名称:"); READ(name) if (NULL=PolyHeadname-'a') printf ("此多项式不存在!n"); break; OutP_Poly(PolyHea

5、dname-'a'); break; case '3': char name1,name2; printf ("请输入加式一的名称:"); READ(name1) if (NULL=PolyHeadname1-'a') printf ("此多项式不存在!请先创建n"); break; printf ("请输入加式二的名称:"); READ(name2) if (NULL=PolyHeadname2-'a') printf ("此多项式不存在!请先创建n"

6、;); break; printf ("请输入要创建的和式的名称:"); READ(name) if (NULL!=PolyHeadname-'a') printf ("此多项式已经存在!n"); break; AddPoly(&PolyHeadname-'a',PolyHeadname1-'a',PolyHeadname2-'a'); OutP_Poly(PolyHeadname-'a'); break; case '4': char name1,n

7、ame2; printf ("请输入被减式的名称:"); READ(name1) if (NULL=PolyHeadname1-'a') printf ("此多项式不存在!请先创建n"); break; printf ("请输入减式的名称:"); READ(name2) if (NULL=PolyHeadname2-'a') printf ("此多项式不存在!请先创建n"); break; printf ("请输入要创建的差式的名称:"); READ(name)

8、if (NULL!=PolyHeadname-'a') printf ("此多项式已经存在!n"); break; DecPoly(&PolyHeadname-'a',PolyHeadname1-'a',PolyHeadname2-'a'); OutP_Poly(PolyHeadname-'a'); break; case '5': printf ("请输入要删除的多项式名称:"); READ(name) if (NULL=PolyHeadname-&

9、#39;a') printf ("此多项式不存在!n"); break; DelPoly(&PolyHeadname-'a'); printf ("多项式%c已删除!n",name); break; case '6': return OK; status CreatPoly(P_Poly* P_PolyHead,int n) /为确保其他子函数正常运行，入口参数要求不含同类项、指数递减 int i=0; P_Poly p,tail; *P_PolyHead=(Poly*)malloc(sizeof(Poly

10、); (*P_PolyHead)->expn=n; tail=*P_PolyHead; printf ("请按照指数递减序输入最简形式的多项式n"); for (;i<n;i+) p=(Poly*)malloc(sizeof(Poly); printf ("请输入第%d项的系数和指数(系数，指数):",i+1); scanf ("%f,%d",&(p->coef),&(p->expn); tail->next=p; tail=p; tail->next=NULL; return OK

11、;void OutP_Poly(P_Poly PolyHead) int i=0; P_Poly p; printf ("%d ",PolyHead->expn); p=PolyHead->next; for (;i<PolyHead->expn;i+) printf ("%f,%d ",p->coef,p->expn); p=p->next; printf ("n");void AddPoly(P_Poly* P_PolyHead,P_Poly PolyHead1,P_Poly PolyHe

12、ad2) int i=0; P_Poly p1,p2,p,tail; p1=PolyHead1->next; p2=PolyHead2->next; *P_PolyHead=(P_Poly)malloc(sizeof(Poly); p=tail=*P_PolyHead; while(p1&&p2) int e1,e2; e1=p1->expn; e2=p2->expn; if (e1>e2) p=(P_Poly)malloc(sizeof(Poly); tail->next=p; tail=p; *p=*p1; p1=p1->next;

13、 i+; else if(e1=e2) float sum_c=p1->coef+p2->coef; if (sum_c!=0.0) p=(P_Poly)malloc(sizeof(Poly); tail->next=p; tail=p; p->coef=sum_c; p->expn=e1; i+; p1=p1->next; p2=p2->next; else if (e1<e2) p=(P_Poly)malloc(sizeof(Poly); tail->next=p; tail=p; *p=*p2; p2=p2->next; i+;

14、 while (p1) p=(Poly*)malloc(sizeof(Poly); *p=*p1; tail->next=p; tail=p; p1=p1->next; i+; while (p2) p=(Poly*)malloc(sizeof(Poly); *p=*p2; tail->next=p; tail=p; p2=p2->next; i+; (*P_PolyHead)->expn=i; tail->next=NULL;void DecPoly(P_Poly* P_PolyHead,P_Poly PolyHead1,P_Poly PolyHead2)

15、 int i=0; P_Poly p1,p2,p,tail; p1=PolyHead1->next; p2=PolyHead2->next; *P_PolyHead=(P_Poly)malloc(sizeof(Poly); p=tail=*P_PolyHead; while(p1&&p2) int e1,e2; e1=p1->expn; e2=p2->expn; if (e1>e2) p=(P_Poly)malloc(sizeof(Poly); tail->next=p; tail=p; *p=*p1; p1=p1->next; i+;

16、 else if(e1=e2) float dif_c=p1->coef-p2->coef; if (dif_c!=0.0) p=(P_Poly)malloc(sizeof(Poly); tail->next=p; tail=p; p->coef=dif_c; p->expn=e1; i+; p1=p1->next; p2=p2->next; else if (e1<e2) p=(P_Poly)malloc(sizeof(Poly); tail->next=p; tail=p; p->coef=-p2->coef; p->expn=p2->expn; p2=p2->next; i+; while (p1) p=(Poly*)malloc(sizeof(Poly); *p=*p1; tail->next=p; tail=p; p1=p1->next; i+; while (p2) p=(Poly*)m