C/C++解答集锦

1.前n项求和？

#include<stdio.h>

int main()

{

int n,i,sum;

sum=0;

while((scanf("%d",&n)!=EOF))

{

sum=0;

for(i=0;i<=n;i++)

sum+=i;

printf("%d\n\n",sum);

}

}

2．输入一个小于或等于九位数的数，输出它是几位数，然后单独顺序输出它的位，最后逆序输出它的位

#include<stdio.h>

int digtal(int n)

{

return (n > 0)? 1 + digtal(n/10) : 0;

}

int single(int n)

{

return (n > 0)? single(n/10),printf("%d ",n%10):0;

}

int niverted(int n)

{

return (n > 0)? (printf("%d",n%10),niverted(n/10)):0;

}

int main()

{

int n;

while((scanf("%d",&n)!=EOF))

{

printf("%d has %d digtals\n",n,digtal(n));

printf("single out is:");

single(n);

printf("\nInverted order output IS:");

niverted(n);

printf("\n\n");

}

}

3．给定一个半径求其周长及面积

#include <iostream>

#include <stdio.h>

#include<iomanip>

using namespace std;

#define PI 3.1416

float girth(float r)

{

float l;

if (r > 0)

l = 2 * PI * r;

return l;

}

float area(float r)

{

float s;

if (r > 0)

s = PI * r * r;

return s;

}

int main()

{

float r;

cout << "please enter raduis:";

while(cin >> r)

{

cout << "girth:l=" << girth(r) << endl;

cout << "area:s=" << area(r) << endl << '\n';

cout << "please enter raduis:";

}

return 0;

}

4.打印九九乘法表

#include <iostream>

#include <stdio.h>

#include<iomanip>

using namespace std;

void main()

{

int i,j;

for (i = 1; i <= 9; i++)

for(j = 1; j <= i; j++)

{

cout << j << '*' << i << '=' << i * j << '\t';

if (j == i)cout << '\n';

}

}

4．1、程序启动后，在控制台中显示“请输入一个数字（10-20）：”的提示信息，并等待用户输入内容

2、读取用户输入的内容，根据用户输入的内容做以下处理：
A、如果用户输入的数字不在 10到 20之间，显示提示“输入不正确，请重新输入数字”
B、如果用户输入的数字正确，依次输出 1到用户输入的数字范围内的数字（使用循环语句输出数字）。如：用户输入 18，在控制台上依次输出
1,2,3..18
3、 C、用户输入“0”，退出程序
#include <stdio.h>

#include <iostream>

using namespace std;

void main()

{

int digit;

cout << "请输入一个数字(10-20)：";

while(cin >> digit)

{

if (digit == 0)

break;

else if ((10 <= digit )&&(digit <= 20))

{

for (int i =1; i <= digit; i++)

{

cout << i;

if (i != digit)

cout << ',';

}

cout << endl;

}

else

cout << "输入不正确，请重新输入数字" << '\n';

cout << '\n';

}

}

5.求任意一点到一条直线的距离

#include <stdio.h>

#include <math.h>

#include <iostream>

using namespace std;

class line;

class point

{

public:

int x,y;

public:

point(int x1,int y1)

{

x=x1;

y=y1;

};

friend double dist(line l,point p);

};

class line

{

public:

int a,b,c;

public:

line(int a1,int b1,int c1)

{

a=a1;b=b1;c=c1;

};

friend double dist(line l,point p);

};

double dist(line l,point p)

{

double d;

d = abs(l.a*p.x + l.b*p.y + l.c)/(sqrt(l.a*l.a + l.b*l.b));

return d;

}

void main()

{

int x,y;

int a,b,c;

cout << "请输入一个点:";

while(cin >> x >> y)

{

cout << "点:" << "(" << x << "," << y << ")" << endl;

cout << "请输入直线的三个参数:";

cin >> a >> b >> c;

printf("%d,%d,%d\n",a,b,c);

printf("直线：%d*x+%d*y+%d=0\n",a,b,c);//cout << "直线：" << "(" << a << "," << b << "," << c << ")" << endl;

point p1(x,y);

line l1(a,b,c);

cout << "他们间的距离为：distance=" << dist(l1,p1) << endl << endl;

cout << "请输入一个点:";

}

system("pause");

}

6.给定两三角形边长，求其面积和

#include <stdio.h>

#include <math.h>

#include <iostream>

using namespace std;

class trig

{

double x,y,z;

double area()

{

double d = (x+y+z)/2;

return sqrt(d*(d-x)*(d-y)*(d-z));

}

public:

trig(int i,int j,int k)

{

x = i;

y = j;

z = k;

}

int judge()

{

if ((z < x+y)&&(x < z+y)&&(y < z+x))

return 1;

else

return 0;

};

friend double twoarea(trig a1,trig a2)

{

return (a1.area() + a2.area());

}

};

void main()

{

trig t1(1,4,5),t2(3,4,5);

if (t1.judge()&&t2.judge())

cout << "两三角形的面积和为:area=" << twoarea(t1,t2) << endl;

else

cout << "不能构成三角形" << endl;

}

7.计算储户三家银行的存款数

#include <stdio.h>

#include <iostream>

using namespace std;

class CBank;

class BBank;

class GBank;

class CBank

{

int balance;

public:

CBank(){balance = 0;}

CBank(int i){balance = i;}

void getblance()

{

cout << "输入中国银行存款数：";

cin >> balance;

}

void disp()

{

cout << "中国银行存款数为：" << balance << endl;

}

friend void total(CBank,BBank,GBank);

};

class BBank

{

int balance;

public:

BBank(){balance = 0;}

BBank(int i){balance = i;}

void getblance()

{

cout << "输入工商银行存款数：";

cin >> balance;

}

void disp()

{

cout << "工商银行存款数为：" << balance << endl;

}

friend void total(CBank,BBank,GBank);

};

class GBank

{

int balance;

public:

GBank(){balance = 0;}

GBank(int i){balance = i;}

void getblance()

{

cout << "输入农业银行存款数：";

cin >> balance;

}

void disp()

{

cout << "农业银行存款数为：" << balance << endl;

}

friend void total(CBank,BBank,GBank);

};

void total(CBank A,BBank B,GBank C)

{

cout << "总款数：" << A.balance + B.balance + C.balance << endl;

}

void main()

{

CBank A;

BBank B;

GBank C;

A.disp();

B.disp();

C.disp();

while(1)

{

A.getblance();

B.getblance();

C.getblance();

total(A,B,C);

cout << endl;

}

}

8.经典测试题，强有力的说明了定义类时、构造函数、析构函数等发生的操作，相当经典，有相当的震撼力

#include <stdio.h>

#include<math.h>

#include<string>

#include <iostream>

using namespace std;

class B

{

int x,y;

public:

B() { x=y=0;cout << "Construcor1" << endl; }

B(int i) { x=i;y=0;cout << "Construcor2" << endl;}

B(int i,int j) { x=i; y=j; cout << "Construcor3" << endl;}

~B() { cout << "Construcor" << endl; }

void print()

{

cout << "x=" << x << ",y=" << y << endl;

}

};

void main()

{

B *ptr;

ptr=new B[3];

ptr[1]=B(5);

ptr[2]=B(2,3);

for (int i = 0; i < 3; i++)

ptr[i].print();

delete[] ptr;

}

执行结果：

9.简单时钟设计

#include <stdio.h>

#include <windows.h>

#include <iostream>

using namespace std;

class CDate

{

int m_nDay;

int m_nMonth;

int m_nYear;//定义年月日的数据成员

int sec,min,hour;//定义时间数据成员

public:

CDate();

CDate(int day,int month,int year);

CTime(int s,int m,int h);

void Display();

void AddDay();

void AddTime();

void SetDate(int day,int month,int year);

void SetTime(int s,int m,int h);

~CDate();

private:

bool IsLeapYear();

};

CDate::CDate(){}

CDate::CDate(int year,int month,int day)

{

m_nDay = day;

m_nMonth = month;

m_nYear = year;

}

CDate::CTime(int s,int m,int h)

{

sec = s;

min = m;

hour = h;

}

void CDate::Display()

{

char day[3];

char month[3];

char year[5];

char secd[3],mind[3],hourd[3];

_itoa(m_nDay,day,10);

_itoa(m_nMonth,month,10);

_itoa(m_nYear,year,10);

_itoa(sec,secd,10);

_itoa(min,mind,10);

_itoa(hour,hourd,10);

printf("当前日期是：%s/%s/%s\n",day,month,year);

if ((sec < 10)&&(min < 10)&&(hour < 10))//为了时间前面加个0，我容易吗我？

printf("当前时间是：0%s:0%s:0%s",hourd,mind,secd);

else if ((sec < 10)&&(min < 10)&&(hour >= 10))

printf("当前时间是：%s:0%s:0%s",hourd,mind,secd);

else if ((sec < 10)&&(min >= 10)&&(hour < 10))

printf("当前时间是：0%s:%s:0%s",hourd,mind,secd);

else if ((sec >= 10)&&(min < 10)&&(hour < 10))

printf("当前时间是：0%s:0%s:%s",hourd,mind,secd);

else if ((sec < 10)&&(min >= 10)&&(hour >= 10))

printf("当前时间是：%s:%s:0%s",hourd,mind,secd);

else if ((sec >= 10)&&(min < 10)&&(hour >= 10))

printf("当前时间是：%s:0%s:%s",hourd,mind,secd);

else if ((sec >= 10)&&(min >= 10)&&(hour < 10))

printf("当前时间是：0%s:%s:%s",hourd,mind,secd);

else

printf("当前时间是：%s:%s:%s",hourd,mind,secd);

}

void CDate::AddTime()

{

sec++;

if (sec > 59)

{

sec = 00;

min++;

if (min > 59)

{

min = 00;

hour++;

if (hour > 23)

{

hour = 00;

AddDay();

}

}

}

return;

}

void CDate::AddDay()

{

m_nDay++;

if (IsLeapYear())

{

if ((m_nMonth == 2)&&(m_nDay == 30))

{

m_nMonth++;

m_nDay = 1;

return;

}

}

else

{

if ((m_nMonth == 2)&&(m_nDay == 29))

{

m_nMonth++;

m_nDay = 1;

return;

}

}

if (m_nDay > 31)

{

if (m_nMonth == 12)

{

m_nYear++;

m_nMonth = 1;

m_nDay = 1;

}

else

{

m_nMonth++;

m_nDay = 1;

}

}

}

void CDate::SetDate(int year,int month,int day)

{

m_nDay = day;

m_nMonth = month;

m_nYear = year;

}

void CDate::SetTime(int h,int m,int s)

{

sec = s;

min = m;

hour = h;

}

CDate::~CDate(){ }

bool CDate::IsLeapYear()

{

bool bLeap;

if ((m_nYear % 4 == 0)&&(m_nYear % 100 != 0)||(m_nYear % 400 == 0))

bLeap = 1;

else

bLeap = 0;

return bLeap;

}

void main()

{

CDate d;

d.SetDate(2012,10,20);//设置日期

d.SetTime(15,05,00);//设置时间

while(1)

{

d.Display();//显示

d.AddTime();//时间计数

Sleep(1000);//延时一秒钟

system("cls");//刷屏

}

}

10．求两个复数的算术运算（利用运算符重载）

#include <stdio.h>

//#include <iomanip>

#include <iostream.h>

//using namespace std;

class complex

{

float real,imag;

public:

complex(float r,float i) {real = r;imag = i;}

complex() {real = 0;imag = 0;}

void print();

friend complex operator+(complex a,complex b);

friend complex operator-(complex a,complex b);

friend complex operator*(complex a,complex b);

friend complex operator/(complex a,complex b);

};

void complex::print()

{

cout << real;

if (imag > 0) cout << "+";

if (imag != 0) cout << imag << "i" << endl;

}

complex operator+(complex a,complex b)

{

complex temp;

temp.real = a.real + b.real;

temp.imag = a.imag + b.imag;

return temp;

}

complex operator-(complex a,complex b)

{

complex temp;

temp.real = a.real - b.real;

temp.imag = a.imag - b.imag;

return temp;

}

complex operator*(complex a,complex b)

{

complex temp;

temp.real = a.real * b.real - b.imag*b.imag;

temp.imag = a.real * b.imag - a.imag*b.real;

return temp;

}

complex operator/(complex a,complex b)

{

complex temp;

float tt;

tt = 1/(b.real*b.real + b.imag*b.imag);

temp.real = (a.real*b.real + a.imag*b.imag)*tt;

temp.imag = (b.real*a.imag - a.real*b.imag)*tt;

return temp;

}

void main()

{

complex c1(2.3,4.6),c2(3.6,2.8),c3;

c1.print();

c2.print();

c3 = c1 + c2;

c3.print();

c3 = c1 - c2;

c3.print();

c3 = c1 * c2;

c3.print();

c3 = c1 / c2;

c3.print();

}

11．编写一个学生和教师的数据输入和显示程序，学生数据有编号、姓名、班级和成绩，教师数据有编号、姓名、职称和部门。要求将编号、姓名输入和显示设计成一个类person，并作为学生数据操作类student和教师数据操作类teacher的基类

#include <stdio.h>

#include <iomanip>

#include <iostream.h>

using namespace std;

class person

{

int number;

char name[10];

public:

void input()

{

cout << "输入编号：";cin >> number;

cout << "输入姓名：";cin >> name;

}

void disp()

{

cout << " 编号" << number << endl;

cout << " 姓名" << name << endl;

}

};

class student:public person

{

char clas[6];

int score;

public:

void input()

{

person::input();

cout << " 班号:"; cin >> clas;

cout << " 成绩:"; cin >> score;

}

void disp()

{

person::disp();

cout << " 班号:" << clas << endl;

cout << " 成绩:" << score << endl;

}

};

class teacher:public person

{

char title[10];

char branch[10];

public:

void input()

{

person::input();

cout << " 职称:"; cin >> title;

cout << " 部门:"; cin >> branch;

}

void disp()

{

person::disp();

cout << " 职称:" << title << endl;

cout << " 部门:" << branch << endl;

}

};

void main()

{

student s1;

teacher t1;

cout << "输入一个学生数据：\n";s1.input();

cout << "输入一个教师数据：\n";t1.input();

cout << "显示一个学生数据：\n";s1.disp();

cout << "显示一个教师数据：\n";t1.disp();

system("pause");

}