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1.

#include 
     
      #include 
      
       #include 
       
        #include "vector.h"int main(){    using namespace std;    using VECTOR::Vector;    ofstream of;    of.open("result.txt");    srand(time(0));    double direction;    Vector step;    Vector result(0.0,0.0);    unsigned int steps = 0;    double target;    double dstep;    cout <<"Enter target distance ( q to quit ): ";    cin >> target;    cout << "Enter step length: ";    cin >> dstep;    of << "Target Distance : " << target << ", Step Size: " << dstep << endl;    for(steps = 0; result.magval() < target; steps++)    {        direction = rand() % 360;        step.reset (dstep, direction, Vector::POL);        result = result + step;        of << steps << ": "<< result << endl;    }    of << "After " << steps << " steps, the subject has the following location:\n";    of << result <
       
      
     

======================================== 答案 =========================================

#include 
     
      #include 
      
       #include 
       
        #include "TVector.h"using namespace std;using namespace n_vector;intmain (void) { ofstream    of;of.open("output.txt");while (true) {double    setp;double    distance;unsigned    cnt_steps = 0;cout << "输入步长：";cin >> setp;if (!cin || setp <= 0) {break;}cin.clear();    // 清空输入缓冲区错误标志位cin.ignore(std::numeric_limits
        
         ::max(), '\n');    // 清空输入缓冲区内容cout << "输入距离：";cin >> distance;if (!cin || distance <= 0) {break;}cin.clear();    // 清空输入缓冲区错误标志位cin.ignore(std::numeric_limits
         
          ::max(), '\n');    // 清空输入缓冲区内容of << "开始>>>>>>>>>>" << endl;TVector    vec(0, 0, TVector::POL);srand((unsigned)time(nullptr));while (vec.getLength() < distance) {vec += TVector(setp, rand()%361, TVector::POL);of << cnt_steps++ << "：" << vec << endl;}of << "结束<<<<<<<<<<" << endl;of << "距离" << distance << "，步长" << setp << "，历经" << cnt_steps << "步走完，终点坐标" << vec << endl;of << "==========\n" << endl;}of.close();cout << endl;return (0);}
         
        
       
      
     

 

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2.答案

double setp; double distance; int times; int max_setps = 0; int min_setps = numeric_limits
     
      ::max(); int sum_setps = 0;
     

......

for (int i = 0; i < times; ++i) {            int cnt_steps = 0;            TVector vec(0, 0, TVector::POL);            cout << i << ":";            while (vec.getLength() < distance) {                vec += TVector(setp, rand()%360, TVector::POL);                ++cnt_steps;            }            cout << cnt_steps << "steps to " << vec << endl;            if (cnt_steps > max_setps) {                max_setps = cnt_steps;    // get max step            }            if (cnt_steps < min_setps) {                min_setps = cnt_steps;    // get min step            }            sum_setps += cnt_steps;       // total steps        }

 7.  11_7_complex0.h

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#ifndef E11_7_COMPLEX0_H#define E11_7_COMPLEX0_H#include 
      
       class Complex{private:    double m_a;    double m_c;public:    Complex();  //default constructor    ~Complex();    Complex(double x1, double y1 );  // constructor    //operator overloading    Complex operator+(const Complex & t) const;    Complex operator-(const Complex & t) const;    Complex operator*(double n) const;    Complex operator*(const Complex & t) const;    Complex operator~() const;    //friend    friend std::ostream & operator<<(std::ostream & os, const Complex & v);    friend std::istream & operator>>(std::istream & is, Complex & t);    friend Complex operator*(double m, const Complex & t);};#endif //E11_7_COMPLEX0_H
      

11_7_comlpex0.cpp

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#include "complex0.h"using std::endl;Complex::Complex(){    m_a = m_c = 0.0;}Complex::~Complex() {}Complex::Complex(double x1, double y1){    m_a = x1;    m_c = y1;}Complex Complex::operator+(const Complex &t) const{    return Complex(t.m_a + m_a, t.m_c + m_c);}Complex Complex::operator-(const Complex & t) const{    return Complex(m_a - t.m_a, m_c - t.m_c);}Complex Complex::operator*(double n) const{    return Complex(m_a * n, m_c * n);}Complex Complex::operator*(const Complex & t) const{    return Complex(t.m_a * m_a - t.m_c * m_c, t.m_c * m_a + t.m_a * m_c);}Complex Complex::operator~() const{    return Complex(m_a, -m_c);}//friendstd::ostream &operator<<(std::ostream & os, const Complex & v){    os << "( " << v.m_a <<", " << v.m_c <<"i )" << endl;}std::istream &operator>>(std::istream & is, Complex & t){    std::cout << "Real: ";    is >> t.m_a;    std::cout << "Imaginary: ";    is >> t.m_c;}Complex operator*(double m, const Complex & t){    return Complex(t.m_a * m, t.m_c * m);}

11_7_main.cpp

---

#include 
      
       using namespace std;#include "complex0.h"int main(){    Complex a(3.0, 4.0);    Complex c;    cout << "Enter a complex number (q to quit):\n";    while (cin >> c)    {        cout << "c is " << c << '\n';        cout << "complex conjugate is " << ~c << '\n';        cout << "a is " << a << '\n';        cout << "a + c is " << a + c << '\n';        cout << "a - c is " << a - c << '\n';        cout << "a * c is " << a * c << '\n';        cout << "2 * c is " << 2 * c << '\n';        cout << "Enter a complex number ( q to quit):\n";    }    cout << "Done!\n";    return 0;}