C语言程序设计（第二版）第9章例题

例9.1

#include<stdio.h>
struct student3{
   int no;
   char name[10];
   int age;
   char sex;
   char addr[50];
   double score;
} ;
void main()
{
 struct student3 s={940114,"李红",19,'F',"杭州下沙学林街80号",655.5};
 printf("%d %s %d %c %s %.1f\n",s.no,s.name,s.age,s.sex,s.addr,s.score);   
}

例9.2

#include<stdio.h>
struct student2{
   char name[10];
   int age;
   float score[5],ave;
};
void main()
{
   struct student2 stu;
   int i;
   stu.ave = 0;
   scanf("%s%d",stu.name,&stu.age);
   for(i=0;i<5;i++)
   {
      scanf("%f",&stu.score[i]);
      stu.ave+=stu.score[i]/5.0;
   }
   printf("Output:\n");
   printf("%-s%-4d\n",stu.name,stu.age);
   for(i=0;i<5;i++)
     printf("%-6.1f",stu.score[i]);
   printf("	average=%6.1f\n",stu.ave);
}

例9.3

#include<stdio.h>
#include<math.h>
struct comp 
{
   double x,y;
   double m;
};
void main()
{
   struct comp s1,s2;
   double compare(struct comp a,struct comp b);
   printf("Input:\n");
   scanf("%lf%lf",&s1.x,&s1.y);
   scanf("%lf%lf",&s2.x,&s2.y);
   if(compare(s1,s2)==0)
     printf("Equal\n");
   else
     printf("Unequal\n");
}
double compare(struct comp a,struct comp b)
{
   a.m=sqrt(a.x*a.x+a.y*a.x);
   b.m=sqrt(b.x*b.x+b.y*b.y);
   return (a.m-b.m);
}

例9.4

#include<stdio.h>
struct comp
{
   double x,y;
   double m;
};
void main()
{
   struct comp s1,s2,z;
   struct comp add(struct comp a,struct comp b);
   printf("Input:\n");
   scanf("%lf%lf",&s1.x,&s1.y);
   scanf("%lf%lf",&s2.x,&s2.y);
   z=add(s1,s2);
   printf("%.2f%+.2fi\n",z.x,z.y);
}
struct comp add(struct comp a,struct comp b)
{
   struct comp c;
   c.x=a.x+b.x;
   c.y=a.y+b.y;
   return c;
}

例9.5

#include<stdio.h>
#include<math.h>
#define N 6
struct comp 
{
   double x,y;
   double m;
};
void main()
{
   struct comp a[N],temp;
   int i,j,k;
   printf("Input complex:\n");
   for(i=0;i<N;i++)
   {
      scanf("%lf%lf",&a[i].x,&a[i].y);
      a[i].m=sqrt(a[i].x*a[i].x+a[i].y*a[i].y);
   }
   for(i=0;i<N-1;i++){
     k=i;
     for(j=i+1;j<N;j++)
       if(a[k].m>a[j].m) k=j;
     temp=a[i];
     a[i]=a[k];
     a[k]=temp;
   }
   printf("After sort:\n");
   for(i=0;i<N;i++)
      printf("%0.1f%+.1fi\n",a[i].x,a[i].y);
}

例9.6

#include<stdio.h>
#include<math.h>
#define N 6
struct comp{
   double x,y;
   double m;
};
void main()
{
 struct comp a[N];
 int i;
 void sort (struct comp *,int);
 printf("Input complex:\n");
 for(i=0;i<N;i++){
  scanf("%lf%lf",&a[i].x,&a[i].y);
  a[i].m=sqrt(a[i].x*a[i].x+a[i].y*a[i].y);
 }   
 sort(a,N);
 printf("After sort : \n");
 for(i=0;i<N;i++)
    printf("  %.1f%+.1fi",a[i].x,a[i].y);
}
void sort(struct comp * pa,int n)
{
   int i,j,k;
   struct comp temp;
   for(i=0;i<n-1;i++)
   {
      k=i;
      for(j=i+1;j<n;j++)
        if((pa+k)->m>(pa+j)->m)
            k=j;
      temp=*(pa+i);
      *(pa+i)=*(pa+k);
      *(pa+k)=temp;
          
   }
}

例9_7

#include<stdio.h>
#include<stdlib.h>
struct student
{
   char name[10];
   float score;
   struct student * next;
};
void main()
{
   struct student * insert(struct student *head);
   void print(struct student * head);
   struct student * head;
   int i,n;
   printf("Input the number of nodes:\n");
   scanf("%d",&n);
   printf("Input nodes:\n");
   head=(struct student *)malloc(sizeof(struct student));
   scanf("%s%f",head->name,&head->score);
   head->next=NULL;
   for(i=1;i<n;i++)
      head=insert(head);
      printf("Output:\n");
      print(head);
}
void print(struct student * head)
{
   struct student *p=head;
   while(p!=NULL){
    printf("%s %.1f\n",p->name,p->score);
    p=p->next;
   }
}
struct student *insert(struct student *head)
{
   struct student *p,*pnew,*pold;
   pnew=(struct student *)malloc(sizeof(struct student));
   scanf("%s%f",pnew->name,&pnew->score);
   p=head;
   if(pnew->score>head->score){
      pnew->next=head;
      head=pnew;
   }
   else{
      while(p!=NULL&&pnew->score<=p->score){
	  pold=p;
	  p=p->next;
	  }
	  pnew->next=p;
	  pold->next=pnew;
   }
   return head;
}

例9_8

#include<stdio.h>
#include<stdlib.h>;
struct student
{
   char name[10];
   float score;
   struct student * next;
};
void main()
{
   struct student * create();
   struct student *pdelete() ;
   void print();
   struct student * head;
   int n;
   printf("Input the number of nodes:\n");
   scanf("%d",&n);
   head=create(n);
   printf("Output all nodes:\n");
   print(head);
   head=pdelete(head,60);
   printf("Output fail-nodes:\n");
   print(head);
}
void print(struct student * head)
{
   struct student *p=head;
   while(p!=NULL){
    printf("%s %.1f\n",p->name,p->score);
    p=p->next;
   }
}
struct student *create(int n)
{
   struct student * head,* pnew,* ptail;
   int i;
   pnew=(struct student *)malloc(sizeof(struct student));
   scanf("%s%f",pnew->name,&pnew->score);
   head=ptail=pnew;
   for(i=1;i<n;i++)
   {
      pnew=(struct student * )malloc(sizeof(struct student));
      scanf("%s%f",pnew->name,&pnew->score);
      ptail->next=pnew;
      ptail=pnew;
   }
   ptail->next=NULL;
   return head;
}
struct student * pdelete(struct student *head,int grade)
{
   struct student *p,*pold;
   p=head;
   while(head!=NULL&&head->score>=grade){
     head=head->next;
     free(p);
     p=head;
   }
   if(head==NULL)
     return head;
   p=head->next;
   pold=head;
   while(p!=NULL){
      if(p->score>=grade){
	    pold->next=p->next;
	    free(p);
	    p=pold->next;}
   else{
     pold=p;
     p=p->next;
   }
   }
   return head;
}