第十一章编程练习(1)

list.h

#pragma once
#ifndef list_H_
#define list_H_
#include 
namespace VECTOR {
	class Move {
		public:
		enum move { RECH, POL };
	private:
		
		double x;       //分量
		double y;		//分量
		double mag;		//需要行走的距离
		double ang;		//角度
		move mode;		//RECH or POL
		void set_x();
		void set_y();
		void set_ang();
		void set_mag();
	public:
		Move();
		Move(double a, double b, move from = RECH);      //构造函数，默认直角坐标显示
		void reset(double a, double b, move from = RECH);	//设置新的坐标值，默认直角坐标显示
		double xval()const { return x; };         //返回分量1的值
		double yval()const { return y; };		//返回分量2的值
		double magval()const { return mag; };	//返回行走距离
		double angval()const { return ang; };	//返回角度
		void polar_mode();						//设置为直角坐标表示
		void rect_mode();						//设置为极坐标表示
												//重载运算符
		Move operator +(const Move & a)const;
		Move operator -(const Move & a)const;
		Move operator -()const;
		Move operator *(double n)const;
		friend Move operator *(double n, const Move & a);
		friend std::ostream & operator <<(std::ostream & os, const Move & a);
	};
}
#endif

function.cpp

#include 
#include "list.h"
#include 
using namespace std;
namespace VECTOR {
	const double Rad_to_deg = 45.0 / atan(1.0);
	void Move:: set_mag()
	{
		mag = sqrt(x*x + y*y);
	}
	void Move::set_ang()
	{
		if (x == 0 && y == 0)
			ang = 0;
		else
			ang = atan2(y, x);
	}
	void Move::set_x()
	{
		x = mag*cos(ang);
	}
	void Move::set_y()
	{
		y = mag*sin(ang);
	}
	Move::Move()
	{
		x = y = mag = ang = 0;
		mode = RECH;
	}
	Move::Move(double a, double b, move from)
	{
		mode = from;
		if (from == RECH)
		{
			x = a;
			y = b;
			set_mag();
			set_ang();
		}
		else if(from==POL)
		{
			mag = a;
			ang = b/Rad_to_deg;
			set_x();
			set_y();
		}
		else {
			cout << "Incorrect 3rd arguament to Move() --"
			<< "Move set to 0\n";
			x = y = ang = mag = 0;
			mode = RECH;
		}
	}
	void Move::reset(double a, double b, move from)
	{
		mode = from;
		if (from == RECH)
		{
			x = a;
			y = b;
			set_mag();
			set_ang();
		}
		else if (from == POL)
		{
			mag = a;
			ang = b;
			set_x();
			set_y();
		}
		else {

			cout << "Incorrect 3rd arguament to Move() --"
				<< "Move set to 0\n";
			x = y = ang = mag = 0;
			mode = RECH;
		}
	}
	void Move::polar_mode()
	{
		mode = POL;
	}
	void Move::rect_mode()
	{
		mode = RECH;
	}
	Move Move::operator +(const Move & a)const
	{
		return Move(x + a.x, y + a.y);
	}
	Move Move::operator -(const Move & a)const
	{
		return Move(x - a.x, y - a.y);
	}
	Move Move::operator -()const
	{
		return Move(-x, -y);
	}
	Move Move:: operator *(double n)const
	{
		return Move(x*n, y*n);
	}
	Move VECTOR::operator*(double n, const Move & a)
	{
		return a*n;
	}
	std::ostream  & operator<<(std::ostream & os, const Move & a)
	{
		if (a.mode == Move::RECH)
		{
			os << "(x,y) = (" << a.x << ", " << a.y << ")";
		}
		else if (a.mode == Move::POL)
		{
			os << "(m,a) = (" << a.mag << ", " << a.ang *Rad_to_deg<< ")";
		}
		else
			os << "Move object mode is invalid.";
		return os;
	}
}

main.cpp

#include "list.h"
#include 
#include 
#include 
int main()
{
	using namespace std;
	using VECTOR::Move;
	srand(time(0));
	double direction;
	Move step;
	Move result(0.0, 0.0);
	unsigned long steps = 0;
	double target;
	double dstep;
	ofstream fout;
	fout.open("Walkman.txt");
	if (!fout)
		cout << "Open file failed!";
	cout << "Enter target distance(q to quite): ";
	while (cin >> target)
	{
		cout << "Enter step length: ";
		if (!(cin >> dstep))
			break;
		fout << "Target Distance : " << target << ", Step Size :" << dstep << endl;
		while (result.magval() < target)
		{
			fout << steps << ": \t" << result<

		fout<