C语言程序设计(张淑华、朱丽莉版)课后习题参考答案

1、2.2. m=dt.month;d=dt.day;if(y%4=0&y%100!=0|y%400=0)ds1=29;/*计算每月的天数是本年第几天*/switch(m)case1:for(i=0;im-1;i+)s+=dsi;s+=d;break;case2:for(i=0;im-1;i+)s+=dsi;s+=d;break;case3:for(i=0;im-1;i+)s+=dsi;s+=d;break;case4:for(i=0;im-1;i+)s+=dsi;s+=d;break;case5:for(i=0;im-1;i+)s+=dsi;s+=d;break;case6:for(i=0;im

2、-1;i+)s+=dsi;s+=d;break;case7:for(i=0;im-1;i+)s+=dsi;s+=d;break;case8:for(i=0;im-1;i+)s+=dsi;s+=d;break;case9:for(i=0;im-1;i+)s+=dsi;s+=d;break;case10:for(i=0;im-1;i+)s+=dsi;s+=d;break;case11:for(i=0;im-1;i+)s+=dsi;s+=d;break;case12:for(i=0;im-1;i+)s+=dsi;s+=d;break;return(s);voidmain()structdateymd

3、;intdys;printf(Inputyearmonthanddayn);scanf(%d,%d,%d,&ymd.year,&ymd.month,&ymd.day);dys=days(ymd);printf(Todayisthefirst%ddaysinthemiddleofthisyear.n,dys);习题九一、选择题1一、选择题1A2D3A二、写出下列程序的运行结果1102911116111213三、编程题1#includestdio.h#defineN10floatfmax=0,fmin=0;floataverage(floatfscore,intn)inti;floatfaver,

4、fsum=fscore0;fmax=fmin=fscore0;for(i=1;ifmax)4D5B6A3*41258fmax=fscorei;elseif(fscoreifmin)fmin=fscorei;fsum+=fscorei;faver=fsum/n;return(faver);voidmain()floatfave,fnumbN;inti;for(i=0;i=a&c=A&cc&a+cb&b+ca)printf(%.2fn,AREA(a,b,c);elseprintf(Itisnotatriangle!n);、选择题1B2D3D4D5C6A7A8C9D10A11A12B13C14A15

5、C二、写出下列程序的运行结果12120344389310485CBADGFE630,307Thedata:844445678910i=5c=B三、编程题1#include#includevoidfun(char*s,int*a,int*b)while(*s!=0)if(*s=65&*s=97&*s=122)*b+=1;/*可用(*b)+;*/s+;voidmain()chars100;intupper=0,lower=0;printf(请输入一串字符：n);gets(s);fun(s,&upper,&lower);printf(upper=%d,lower=%dn,upper,lower);2

6、#includevoidfun(int*p1,int*p2)intp;p=*p1;*p1=*p2;*p2=p;voidmain()inta,b,*p11,*p22;scanf(%d,%d,&a,&b);p11=&a;p22=&b;if(a=a&ch=z)ch=ch-32;fputc(ch,fp);fclose(fp);/*以下是从文件中读出数据，并在屏幕上显示。在本题中可不写*/fp=fopen(test,r);while(ch=fgetc(fp)!=EOF)putchar(ch);printf(n);fclose(fp);2#includestdio.h#includestdlib.h#de

7、fineN5structstudentcharnum10;charname9;intscore3;floatavg;stuN;voidmain()inti,j,sum;FILE*fp;for(i=0;iN;i+)printf(Pleaseinputthedataofthe%d-thstudentsn,i);printf(studentID:);scanf(%s,stui.num);printf(name:);scanf(%s,);sum=0;for(j=0;j3;j+)printf(score%d:,j);scanf(%d,&stui.scorej);sum+=stui.scorej;stui.avg=sum/3.0;/*将数据写入文件*/fp=fopen(stud,w);for(i=0;iN;i+)if(fwrite(&stui,sizeof(structstudent),1,fp)!=1)printf(Filewriteerror!n);fclose(fp);/*以下是从文件中读出数据，并在屏幕上显示。在本题中可不写*/fp=fopen(stud,r);for(i=0;iN;i+)fread(&stui,sizeof(structstu