c++课后题答案 钱能第二版.doc

1-1#includeusing namespace std; void main()coutIm a studentendl;1-2#includeusing namespace std;int i,j;void main()for(i=1;i=4;i+)for(j=1;j=4-i;j+)cout ;for(j=1;j=2*i-1;j+)cout*;coutendlendl;for(i=1;i=3;i+)for(j=1;j=i;j+)cout ;for(j=1;j=(7-2*i);j+)cout*;coutendlendl;2-13#includeusing namespace std;int i,j;void main()for(i=1;i=9;i+)coutit;for(i=1;i=9;i+)cout-t;coutendlendl;for(i=1;i=9;i+) /下三角形式for(j=1;j=i;j+)/couti*jt;/coutendl;coutendlendl; for(i=1;i=9;i+) /shang三角形式coutti;for(i=0;i9;i+)coutt-;coutendlendl;for (i=1;i=9;i+) for(j=1;j=i;j+)coutt;for(j=i;j=9;j+)/couti*jt;/coutendl;3-3#include#include#include using namespace std; void main() int a11=6,3,7,1,4,8,2,9,11,5;vector ve(a,a+10);int he=0;int sum=0;float average;float s;for(int i=0;ive.size();i+)sum+=vei;average=sum/ve.size();for( i=0;ive.size();i+)he+=(vei-average)*(vei-average);s=sqrt(he/ve.size();couts=sendl;4-6#include#include#includeusing namespace std;void main() int a=0; ifstream in(D:aaa.txt); for(string s;getline(in,s);) for(istringstream sin(s);sina;) if(a%3=0)&(a%5=0)&(a%7=0) couta能同时被3 5 7整除endl; else if(a%3=0)&(a%5)&(a%7) couta能被3整除 不能被5整除 也不能被7整除endl; else if(a%3)&(a%5=0)&(a%7) couta能被5整除 不能被3整除 也不能被7整除endl; else if(a%3)&(a%5)&(a%7=0) couta能被7整除 不能被3整除 也不能被5整除endl; else if(a%3)&(a%5)&(a%7) couta不能被3 5 7 任意一个整除endl; 4-8#includeusing namespace std;void transform(int );int n;void main() /十进制数转换为二进制数cout输入要转换的十进制整数：num;transform(num); void transform(int n)if (n2)cout=2)transform(n/2);coutn%2; 5-5#include#include#include#include#includeusing namespace std;typedef vectorvector vii;/-vector read()vectora;ifstream in(D:aaa.txt);for(string s;getline(in,s);) int c; for(istringstream sin(s);sinc;) a.push_back (c);if(a.empty()coutNO ELement!endl;elsecout从磁盘中读取数据输出结果是：endl;for(int i=0;ia.size();i+) coutai ; /输出读取的数据 coutendlendl; return a; /- int bit_twice_sum(int a) int sum=0; for(int x=a;x;x/=10)sum+=(x%10)*(x%10); return sum; /- bool compare(int sum1,int sum2) return bit_twice_sum(sum1)bit_twice_sum(sum2); /- void insert_cout(vectorve) cout请输入你想插入的数：num; ve.push_back(num); sort(ve.begin(),ve.end(),compare); coutendl插入数之后，再按各位数字平方之和的大小输出：endl; for(int i=0;ive.size();i+) coutvei ; coutendl; /-void main() vectorv0=read(); sort(v0.begin(),v0.end(),compare); coutendl按各位数字平方之和的大小输出：endl; for(int i=0;iv0.size();i+) coutv0i ; coutendl; insert_cout(v0); /-8-1#include#includeusing namespace std;/-class Pointprotected:double x,y; /x y 轴分量public:void set(double ix,double iy)/设置坐标x=ix;y=iy;/-double xoffset()/取y轴坐标分量return x;/-double yoffset()/取x轴坐标分量return y;/-double angle()/取点的极坐标return (180/3.14159)*atan2(y,x);/-double radius()/取点的极坐标半径return sqrt(x*x+y*y);void Point: add()x+=5;y+=6;coutx=xendly=yendl;void main()Point p;double x,y;coutEnter x and y:xy;p.set(x,y);coutangle=p.angle()endlradius=p.radiusendlx offset=p.xoffset()endly offset=p.yoffset()endl;p.add();8-3#include#includeusing namespace std;class Dateprivate:int year,month,day;public:void set(int d,int m,int y);void add();void print();void Date:set(int d,int m,int y)year=y;month=m;day=d;void Date:add()day=day+1;/cout加一天之后日期是：dayendl;void Date:print()coutsetfill(0);coutsetw(2)day/setw(2)month/setw(4)yearendl;/coutsetfill( );void main()Date d1,d2;d1.set(10,4,2012);d1.print();d2.set(10,4,2012);d2.add();d2.print();8-4/*多文件结构*/Time.cpp#includeTime.h void Time:set(int h,int m,int s)hour=h;minite=m;second=s;void Time:print()setfill(0);coutsetw(2)hour:setw(2)minite:setw(2)secondendl;#includeTime.h/主函数void main()Time t;t.set(14,47,39);t.print();9-1#includeusing namespace std;class MyClassint number;public:MyClass();MyClass(int);MyClass();void Display();/-MyClass:MyClass()coutConstructing normally.n;/-MyClass:MyClass(int m):number(m)coutConstructing with a number:numberendl;/-void MyClass:Display()coutDisplay s number:numberendl;/-MyClass :MyClass()coutDestructing.n;/-void main()MyClass obj1;MyClass obj2(20);obj1.Display();obj2.Display();/-9-3#includeusing namespace std;/-class CATint *itsAge;public:CAT():itsAge(new int(5)CAT()delete itsAge;int GetAge() const return *itsAge;void SetAge(int age)*itsAge=age;/-void main()CAT friskey;coutfriskeys age:friskey.GetAge()endl;coutSetting friskey to 6n;friskey.SetAge(6);coutCreating boot