C++语言程序设计宁涛课后参考答案

习题1选择题（1）D（2）D（3）C（4）D（5）C习题2选择题（1）D（2）C（3）A（4）B（5）C（6）A（7）B（8）C2．读程序写结果（1）20，5，100（2）5，30，30（3）1，5，6（4）6，5，6（5）1，6，9（6）8，5，8习题31.选择题（1）D（2）A（3）B（4）D（5）C（6）B（7）D（8）A（9）C（10）A2．编程题（1）main(){ inta,n,count=1,sn=0,tn=0; printf("请输入a和n的值（空格分隔）:\n"); scanf("%d%d",&a,&n); printf("a=%dn=%d\n",a,n); while(count<=n) { tn=tn+a;//tn为n个a组成数的值。sn=sn+tn; a=a*10; ++count; } printf("a+aa+……=%d\n",sn);}（2）#include<iostream>usingnamespacestd;main(){inttmp,n,rn(0);cin>>n;tmp=n;for(inti=0;i<10;i++){if(tmp>0){rn=rn*10+tmp%10;tmp=tmp/10;}elsebreak;}cout<<rn<<endl;if(n==rn)cout<<"这是回文数!"<<endl;elsecout<<"这不是回文数!"<<endl;}（3）#include<iostream>usingnamespacestd;main(){for(inti=0;i<26;i++)cout<<char('A'+i);cout<<endl;for(i=0;i<26;i++)cout<<char('Z'-i);}3．读程序写结果(1)sum=25(2)1习题41.选择题（1）A（2）B（3）A（4）A（5）C（6）D（7）B（8）B2.程序补充(1)if(y==1)(2)returnx;(3)else(4)return(x*GetPower(x,y-1));3.编程题(1)递归#include<iostream.h>intf(intn){ if(n==1)return1; elsereturnn*f(n-1);}voidmain(){longsum=0; for(inti=1;i<=5;i++) sum+=f(i);cout<<"1!+2!+...+5!="<<sum<<endl;}非递归#include<iostream.h>intf(intn){intm=1; for(intj=1;j<=n;j++) m=m*j; returnm;}voidmain(){longsum=0; for(inti=1;i<=5;i++) sum+=f(i);cout<<"1!+2!+...+5!="<<sum<<endl;}(2)#include<iostream>usingnamespacestd;inthcf(intx,inty){while(x!=y){if(x>y)x=x-y;elsey=y-x;}returny;}inticd(intx,inty){returnx*y/hcf(x,y);}voidmain(){ inta,b;cin>>a>>b;cout<<"最大公约数为:"<<hcf(a,b)<<"最小公倍数为:"<<icd(a,b)<<endl;}(3)#include<iostream.h>intf(int);voidg(int);voidmain(){inti;for(i=2;i<=100;i++){ if(f(i))cout<<i<<"isprime"<<endl; else { cout<<i<<"isnotprime"<<endl; cout<<i<<"="; g(i); cout<<endl; }}}intf(inti){ for(intj=2;j<=i/2;j++) { if(i%j)continue; else { return0; break; } } return1;}voidg(inti){ for(intj=2;j<=i/2;j++) { if((i%j==0)&&f(j)) { cout<<j<<"*"; if(f(i/j)) { cout<<i/j; gotolabel; } elseg(i/j);label:break; } }}4.读程序写结果5习题51.根据extern的定义查找错误。选择题（1）C（2）B（3）C（4）B（5）D3读程序写结果.3,1习题6选择题（1）C（2）C（3）B（4）B（5）B（6）B（7）C（8）A（9）A（10）C（11）C（12）D（13）A（14）A2.编程题1)采用直观的“选择排序法”进行排序，基本步骤如下：（1）将a[0]依次与a[1]-a[n-1]比较，选出小者与a[0]交换；最后a[0]为a[0]-a[n-1]中最小者;（2)将a[1]依次与a[2]-a[n-1]比较，选出小者与a[1]比较；最后a[1]为a[1]-a[n-1]中最小者；（3）同理，从i=2到i=n-1,将a[i]依次与a[i+1]-a[n-1]比较，选出较小者存于a[i]中。满足下列情况属于小者；（1）同为奇数或偶数，值较小者。（2）奇数、偶数中的奇数。程序如下:#include<iostream>usingnamespacestd;voidmain(){constintMaxN=10;inta[MaxN]={10,9,8,7,6,5,4,3,2,1};for(intn=0;n<MaxN;n++){cin>>a[n];if(a[n]<0)break;}for(inti=0;i<n;i++)cout<<a[i]<<"\t";cout<<end1<<"n="<<n<<end1;for(i=0;i<n-1;i++)for(intj=i+1;j<n；j++)if((a[i]%2==a[j]%2)&&a[i]>a[j]||a[i]%2<a[j]%2){intt;t=a[i];a[i]=a[j];a[j]=t;}for（i=0;i<n;i++）cout<<a[i]<<"\t";}2)杨辉三角形有如下规律:(1）每行第一个数与最后一个数为1。(2)每行其他数为前一行对应位置的前、后两数之和。采用数组a[i][j]存储第i行j列的数:(1)a[i][0]=1,a[i][i]=1;(i=0,1,2,...)(2)a[i][j]=a[i-1][j-1]+a[i-1][j];(j=1,2,3,...)#include<iosteram>#include<iomanip>usingnamespacestd;voidmain(){constintMaxN=10;inta[MaxN][MaxN];for(inti=0;i<MaxN;i++){a[i][0]=1;a[i][i]=1;for(intj=1;j<i;j++)a[i][j]=a[i-1][j-1]+a[i-1][j];}for（i=0;i<MaxN;i++）{cout<<setw((MaxN-i)*5/2);for(intj=1;j<=i;j++)cout<<a[i][j]<<setw(5);cout<<endl;}}3)程序如下：#include<iosteram>usingnamespacestd;voidmain(){charstr[180];cin>>str;intk=strlen(str);for（inti=0;i<k;i++）cout<<str[k-i-1];}4)矩阵乘积的程序如下：#include<iosteram>usingnamespacestd;voidmain(){constintM=3,K=2,N=4;inta[M][K]={{1,2},{3,4},{5,6}};intb[K][N]={{1,0,1,1},{0,1,0,1}};intc[M][N]={0};for（inti=0;i<M;i++)for（intj=0;j<N;j++）for（intk=0;k<K;k++）c[i][j]=c[i][j]+a[i][k]*b[k][j];for（i=0;i<M;i++){for（intj=0;j<N;j++）cout<<c[i][j]<<"\t";cout<<endl;}}习题7答案选择题（1）B（2）C（3）C（4）D（5）B（6）B（7）C（8）D（9）D（10）A（11）D（12）A（13）B（14）D2.读程序写结果(1)6friday(2)-5,2,3-5,-12,3-5,-12,-7习题8答案选择题D（2）B（3）D（4）D（5）A读程序写结果（1）WangWu（2）2001-lisi-88-66.4-78.5编写程序#include<iostream>usingnamespacestd;structstudent{ intnum; charname[10]; floatscore[2];};voiddisplay(student*p,intn){ for(inti=0;i<n;i++,p++) cout<<p->num<<"\t" <<p->name<<"\t" <<p->score[0]<<"\t" <<p->score[1]<<endl;}main(){ studentstu[3]={ {1,"张三",58,65}, {2,"李四",96,75}, {3,"王五",76,80}}; display(stu,3);}习题9答案选择题（1）A（2）B（3）C（4）B（5）A（6）A（7）C（8）B（9）A（10）B（11）B（12）D（13）D（14）A（15）B（16）D（17）B（18）B（19）A（20）C2.程序补充(1)①usingnamespacestd;②public:③i=ii;④A(A&b)⑤intA::j=0;(2)①intages;ages=ages+years;3.读程序写结果(1)TP()iscallledTP(int,int)iscalledx=2,y=3(2)1678378x=2,y=3n=64.编程题(1)#include<iostream.h>classdate{inty,m,d;public: date(intyy=2000,intmm=1,intdd=1); ~date(){} voidshow(); voidset(int,int,int);};date::date(intyy,intmm,intdd){y=yy;m=mm;d=dd;}voiddate::show(){cout<<y<<"/"<<m<<"/"<<d<<endl;}voiddata::set(intyy,intmm,intdd){y=yy;m=mm;d=dd;}main(){datea(2000,11,30);a.set(2006,11,29)a.show();}(2)#include<iostream>#include<cmath>usingnamespacestd;classCtriangle{public:Ctriangle(doublex,doubley,doublez){a=x;b=y;c=z;}doubleGetPerimeter(){returna+b+c;}doubleGetArea(){doublep=GetPerimeter()/2;returnsqrt(p*(p-a)*(p-b)*(p-c));}voiddisplay(){cout<<"crtiangle:"<<"a="<<a<<""<<"b="<<b<<""<<"c="<<c<<endl;cout<<"perimeter:"<<GetPerimeter()<<endl;cout<<"Area:"<<GetArea()<<endl;}private:doublea;doubleb;doublec;};main(){CtriangleT(3,4,5);T.display();}(3)#include<iostream>usingnamespacestd;classDate{public:intdays(intyear,intmonth){boolleap;if((year%400==0)||(year%4==0&&year%100!=0))leap=true;elseleap=false;switch(month){case1:case3:case5:case7:case8:case10:case12:return31;case4:case6:case9:case11:return30;case2:if(leap)//是否闰月return29;elsereturn28;break;}}Date(inty=1980,intm=1,intd=1){if(m>12||m<1){cout<<"Invalidmonth!"<<endl;m=1;}if(d>days(y,m)){cout<<"Invalidday!"<<endl;d=1;}day=d;year=y;month=m;}voidNewDay(){if(day<days(year,month))day++;else{day=1;month++;if(month==13){year++;month=1;}}}voiddisplay(){cout<<year<<"-"<<month<<"-"<<day<<endl;}private:intyear;//年intmonth;//月intday;//日}main(){DateD1(2006,12,31);D1.display();D1.NewDay();cout<<"afteraday:";D1.display();DateD2(2008,2,29);D2.display();D2.NewDay();cout<<"afteraday:";D2.display();}(4)#include<iostream>#include<string>usingnamespacestd;classStudent//定义学生类student{public:Student(charID[],charname[],doubleg1,doubleg2,doubleg3){num++;strcpy(this->ID,ID);strcpy(this->name,name);grade1=g1;grade2=g2;grade3=g3;sum1=sum1+g1;sum2=sum2+g2;sum3=sum3+g3;}voiddisplay(){cout<<ID<<"\t"<<name<<"\t"<<grade1<<"\t"<<grade2<<"\t"<<grade3<<endl;}doubleaverage1(){returnsum1/num;}doubleaverage2(){returnsum2/num;} doubleaverage3(){returnsum3/num;}private:charID[10];charname[12];doublegrade1;doublegrade2;doublegrade3;staticdoublesum1;staticdoublesum2;staticdoublesum3;staticintnum;};intStudent::num=0;doubleStudent::sum1=0;doubleStudent::sum2=0;doubleStudent::sum3=0;main(){Studentstu1("200606264","Li_Weiwei",88,75,91);stu1.display();Studentstu2("200602164","Chen_hanfu",86,78,93);stu2.display();Studentstu3("200608079","Zhan_gaolin",94,69,97);stu3.display();cout<<"Theaveragegradeofcourse1:"<<stu1.average1()<<endl;cout<<"Theaveragegradeofcourse2:"<<stu2.average2()<<endl;cout<<"Theaveragegradeofcourse3:"<<stu3.average3()<<endl;}习题10答案选择题（1）A（2）A（3）A（4）B（5）A（6）A（7）B（8）C（9）B（10）B2.程序补充(1)①Base::fun();(2)①intid;②intssid③publicA④char*name;⑤A(ssid)⑥publicA⑦char*department;(3)①x=xx;②y=yy;③publicPoint④Point(xx,yy)⑤publicPoint⑥Point(xx,yy)⑦radius=r;3.读程序写结果(1)Currentvalueisofjis0Currentvalueisofjis10x=2,y=3习题11答案选择题（1）C（2）B（3）B（4）C（5）B（6）C（7）B（8）A（9）C（10）C（11）A（12）A（13）D（14）D（15）A（16）B（17）C2.读程序写结果(1)x=1000y=2000z=3000x=1000y=2000z=3000(2)funcinclassC funcinclassC funcinclassC(3)Totalis11Totalis11Totalis