*dp=x-y;
        }
        main(  )
        { int a,b,c,d;
          a=4;b=3;
          ast(a,b,&c,&d);
          printf("%d %d/n",c,d);
         }

(9)以下程序的功能是:人键盘上输入若干个学生的成绩, 统计并输出最高成绩和最低成绩,当输入负数时结束输入.请填空.
        main(  )
        { float x,amax,amin;
          scanf("%f",&x);
          amax=x;
          amin=x;
          while(     9    )
           { if(x>amax)amax=x;
           if(  10  )amin=x;
              scanf("%f",&x);
         }
         printf("\namax=%f\namin=%f\n",amax,amin);
       }

(10)下面程序通过函数average计算数组中各元素的平均值,请填空。
        float average(int * pa,int n)
        { int i;
          float avg=0.0;
          for(i=0;i
           main(  )
           { FILE * fp;
             char ch,fname[10];
             printf("lnput the name of file\n");
             gets(fname);
             if((fp=    16    )==NULL)
             { printf("Cannot open\n");    exit(0);}
             printf("Enter data\n");
             while((ch=getchar(  ))!='#')
                        fputc(    17    ,fp);
             fclose(fp);
            }