c语言程序设计课后习题解答

第3章习题解答第1章语言程序主要由预办理命令、函数、说明等构成。填空分号(2)main(3)3.源程序：#include<>main( ){printf(“*************************n”);printf(“HelloWorld!n”);printf(“*************************”);}4.源程序：#include<>main( ){inta,b,c;/*定义变量*/scanf(“%d”,&a);/*输入第一个整数*/scanf(“%d”,&b);/*输入第二个整数*/c=a-b;/*计算差*/printf(“%d-%d=%d”,a,b,c);/*输出结果}5.(1)<>(2)x=10;(3)printf(“s=%dn”,s);

*/第2章1.cabgaded=4,y=6x=4,y=3=3,y=64.165.#include<>main( ){inta,b,c;scanf("%d%d",&a,&b);c=a*b;printf("%d*%d=%d",a,b,c);}第3章1.(1)b(2)b(3)d(4)a(5)b2.(1)&a,&b(2)l,s3.printf(“x=%.2f,y=%.2fn”,x,y);4.#include<>main( ){intnum1,num2,num3,sum;floataverage;scanf("%d%d%d",&num1,&num2,&num3);sum=num1+num2+num3;average=sum/;printf("sum=%d,average=%.2f\n",sum,average);}5.#include<>main( ){inthour,minute,second,total;/*定义变量代表时、分、秒和总秒数*/scanf("%d",&total);hour=total/3600;minute=total%3600/60;second=total%3600%60;printf("%dhours:%dminutes:%dseconds\n",hour,minute,second);}第4章1.(1)a(2)b(3)b(4)b(5)b2.03.(1)6(2)4(3)1(4)14.#include<>main( ){intx,y;scanf("%d",&x);if(x>-5&&x<0)y=5*x;if(x==0)y=-1;if(x>0&&x<10)y=2*x+1;printf("x=%d,y=%d\n",x,y);}5.#include<>main( ){intscore,rank;/*score

表示成绩

,rank

表示级别

*/printf("Pleaseinputscore:");scanf("%d",&score);rank=score/10;switch(rank){case10:case9:printf("case8:printf("

成绩等级为：成绩等级为：

A\n");break;B\n");break;case7:printf("case6:printf("default:printf("

成绩等级为：成绩等级为：成绩等级为：

C\n");break;D\n");break;E\n");break;}}6.#include<>voidmain( ){intn;printf("Pleaseinputthedigit:");scanf("%d",&n);switch(n){case1:printf("Jan\n");break;case2:printf("Feb\n");break;case3:printf("Mar\n");break;case4:printf("Apr\n");break;case5:printf("May\n");break;case6:printf("Jun\n");break;case7:printf("Jul\n");break;case8:printf("Agu\n");break;case9:printf("Sep\n");break;case10:printf("Oct\n");break;case11:printf("Nov\n");break;case12:printf("Dec\n");break;}}第5章1.babdd2.7,13.y=-14.m=65.10,1435ABABCDCDinclude<>main( ){inti;longintsum=0;for(i=2;i<=200;i+=2)sum+=i;printf("2+4+6+...+200=%ld",sum);}10.#include<>main( ){longintn;intsum=0;printf("Pleaseinputthenber:");scanf("%ld",&n);while(n!=0){sum+=n%10;n/=10;}printf("%d\n",sum);}第6章1.dbdca6895.12,66.(1)i--(2)n7.(1)chark;(2)i<j8.#include<>main( ){floata[10];inti;floatsum=0,average;for(i=0;i<10;i++){printf("a[%d]=?",i);scanf("%f",&a[i]);sum+=a[i];}average=sum/10;printf("averageis%.2f\n",average);}9.#include<>#defineN10main( ){inta[N],i,target,found;for(i=0;i<N;i++)scanf("%d",&a[i]);printf("Pleaseinputanumber:");scanf("%d",&target);i=0;while(i<N&&target!=a[i])i++;found=i<N?i:-1;printf("%d\n",found);}10.#include<>#defineN80main( ){charstr[N];intlen=0,i=0;printf("Pleaseinputastring:");gets(str);while(str[i++]!=0)len++;printf("thelengthofstringis%d.\n",len);}第7章21136164.(1)func(2)m++91,6,3,2,32,5,1,2,3,-28.#include<>intfun(inta,intb,intc);main( ){inta,b,c,max;printf("Pleaseinputthreenumbers:");scanf("%d%d%d",&a,&b,&c);max=fun(a,b,c);printf("Maxis%d.\n",max);}intfun(inta,intb,intc){intmax;max=a>b?(a>c?a:c):(b>c?b:c);returnmax;}9.#include<>longintsum(intn);main( ){intn;printf("n=?");scanf("%d",&n);printf("Sum=%ld.\n",sum(n));}longintsum(intn){if(n==1)return1;elsereturnsum(n-1)+n;}10.#include<>voidfun(n);main( ){intn;printf("n=?");scanf("%d",&n);fun(n);}voidfun(n){if(n==0)return;else{fun(n/2);printf("%-2d",n%2);}}第8章1.bdbcc34565.3456.123456b[i]bcdefghap=sum#include<>#include<>main( ){charstr[80];char*p1,*p2;gets(str);p1=str;p2=str+strlen(str)-1;while(p1<p2&&*p1++==*p2--);puts(p1<p2?"不是回文":"是回文");}第9章1.a.#defineF(x)(x)*(x)*(x)b.#defineF(x)(x)%4c.#defineF(x,y)(x)*(y)<100?1:02.44#defineDOUBLE(x)2*(x)3.d-20Nisundefined7.5y=68.#include<>#defineSWAP(a,b){inttemp;temp=a;a=b;b=temp;}main( ){intx,y;printf("x=?");scanf("%d",&x);printf("y=?");scanf("%d",&y);SWAP(x,y)printf("x=%d,y=%d.\n",x,y);}第10章1.structstudent{intsno;charsname[10];charsex;}stu1,stu2;12合法的有a,b,d改成改成改成a,b,c,d(说明：变量b有确立的值以后，b++是合法的。)改为typedefstructproduct{charname[10];floatprice;}PRODUCT;PRODUCTproducts[10];6.structemployeeprintemp(emp)24398#include<>structtime_struct{inthour;intminute;intsecond;};main( ){structtime_structtime;printf("Inputtime?\n(Example18:28:38)\n");scanf("%d:%d:%d",&,&,&;printf("Timeis%d:%d:%d\n",,,;}9.#include<>structtime_struct{inthour;intminute;intsecond;}time;voidenter_time( );voiddisplay_time( );main( ){enter_time( );display_time( );}voidenter_time( ){printf("Enterthetime(example18:28:38)?");scanf("%d:%d:%d",&,&,&;}voiddisplay_time( ){printf("Timeis%d:%d:%d.\n",,,;10.#include<>#defineN3structhotel{charname[31];/*酒店名称*/charaddress[31];/*酒店地点*/intgrade;/*酒店级别*/floataverage_charge;/*均匀房价*/intnumber;/*房间数目*/}h[N]={{"h1","上海路",5,,80},{"h2","北京大街",5,,70},{"h3","南京大街",3,,100}};main( ){intgrade,i;printf("请输入级别(3-5)?");scanf("%d",&grade);for(i=0;i<N;i++)if(h[i].grade==grade)printf("名称:%s\n地点:%s\n级别:%d\n均匀房价%.2f\n

房间数目

:%d\n",h[i].name,h[i].address,h[i].grade,h[i].average_charge,h[i].number);}第11章1.cdbbbBasicanfgetc(fp)“”,“w”5.#include<>#include<>#include<>typedefstructEmployee{intid;charname[20];chargender[20];intage;charaddress[20];}Employee;intmain(void){FILE*fp;charanother,choice;Employeeemp;longintrecsize;fp=fopen("","rb+");if(fp==NULL){fp=fopen("","wb+");if(fp==NULL){printf("Can'tOpenFile");exit(0);}}recsize=sizeof(emp);while(1){printf("1.增添记录2.显示男职工3.退出\n");printf("Enteryourchoice(1-3):");fflush(stdin);scanf("%c",&choice);switch(choice){case'1':fseek(fp,0,SEEK_END);another='Y';while(another=='Y'||another=='y'){printf("输入信息(id姓名性别年纪地址):\n");scanf("%d%s%s%d%s",&,&,&,&,&;fwrite(&emp,recsize,1,fp);printf("能否连续(Y/N):");fflush(stdin);another=getchar( );}break;case'2':printf("学号\t姓名\t性别\t年纪\t地址\n");rewind(fp);while(fread(&emp,recsize,1,fp)==1)if(strcmp,"男")==0)printf("%d\t%s\t%s\t%d\t%s\n",,,,,;break;case'3':fclose(fp);exit(0);}}}6.#include""#include""#defineM2#definestustructstudentstu{intnum;charname[20];floats1;floats2;floats3;floatavg;};main( ){stust[M];FILE*fp;inti;printf("请输入5名同学生的成绩，依据学号,姓名,成绩1,成绩2,成绩3的次序,中间用空格隔开:\n");for(i=0;i<M;i++){scanf("%d%s%f%f%f",&st[i].num,st[i].name,&st[i].s1,&st[i].s2,&st[i].s3);st[i].avg=(st[i