C++ Primer Plus 第6版第九章課後習題

#1

// 1.cpp 
#include <iostream>
#include "1.h"

int main()
{
	golf gf; 
	// init golf
	setgolf(gf, "Kan SCP", 80);
	// show golf
	showgolf(gf);
	// input golf
	setgolf(gf);
	// show golf
	showgolf(gf);
	// reset hc
	handicap(gf, 12);
	showgolf(gf);

	return 0;
}

void setgolf(golf & g, const char * name, int hc) {
	strcpy(g.fullname, name);
	g.handicap = hc;
}

int setgolf(golf & g) {
	using std::cout;
	using std::cin;

	cout << "Enter your fullname: ";
	cin.getline(g.fullname, Len);
	cout << "Enter your handicap: ";
	(cin >> g.handicap).get();

	if (!strlen(g.fullname))
		return false;
	return true;
}

// reset handicap
void handicap(golf & g, int hc) {
	g.handicap = hc;
}

// show golf struct data
void showgolf(const golf & g) {
	using std::cout;
	using std::endl;

	// output your fullname and handicap
	cout << "You fullname: " << g.fullname << endl;
	cout << "You handicap: " << g.handicap << endl;
}

#2

// 2.cpp
#include <iostream>
#include <string>
using namespace std;
void strcount(const string & str);

int main()
{
	string str;
	//char next;

	cout << "Enter a line:\n";
	getline(cin, str);
	while (str != "") {
		strcount(str);
		cout << "Enter next line (empty line to quit):\n";
		getline(cin, str);
	}
	cout << "Bye\n";
	return 0;
}

void strcount(const string & str) {
	static int total = 0;
	int count = 0;

	cout << "\"" << str << "\" contains ";
	count = str.size();
	total += count;

	cout << count << " characters\n";
	cout << total << " characters total\n";
}

#3

// 3.cpp 
#include <iostream>
#include <new>
using namespace std;
struct chaff {
	char dross[20];
	int slag;
};

const int LEN = 512;
const int N = 2;

int main() 
{
	char buffer[LEN];
	chaff * jok1 = new chaff[N];
	chaff * jok2 = new (buffer) chaff[N];

	for (int i = 0; i < N; i++) {
		strcpy(jok1[i].dross, "JOK1");
		strcpy(jok2[i].dross, "JOK2");
		jok1[i].slag = jok2[i].slag = 1000 + i;
	}

	for (int i = 0; i < N; i++) {
		cout << "#Index " << i << endl;
		cout << jok1[i].dross << " at " << &jok1[i].dross << endl;
		cout << jok1[i].slag << " at " << &jok1[i].slag << endl;
		cout << jok2[i].dross << " at " << &jok2[i].dross << endl;
		cout << jok2[i].slag << " at " << &jok2[i].slag << endl;
	}

	delete[] jok1;
	return 0;
}

#4

sales.h

#ifndef _SALES_H
#define _SALES_H

// 定義名稱空間 SALES
namespace SALES {
	const int QUARTERS = 4;
	struct Sales {
		double sales[QUARTERS];
		double average;
		double min;
		double max;
	};
	void setSales(Sales & s, const double ar[], int n);
	void setSales(Sales & s);
	void showSales(const Sales & s);
}

#endif

sales.cpp

// sales.cpp
#include <iostream>
#include "sales.h"
using namespace SALES;

int main()
{
	Sales saleroom;
	double ar[QUARTERS] = { 3.2, 1.2, 4.8, 7.2 };

	// 非互交式設置
	setSales(saleroom, ar, QUARTERS);
	showSales(saleroom);
	// 互交式設置
	setSales(saleroom);
	showSales(saleroom);

	return 0;
}

saless.cpp

// saless.cpp
#include <iostream>
#include "sales.h"

// SALES 版本
namespace SALES {
	using std::cout;
	using std::cin;
	using std::endl;

	void setSales(Sales & s, const double ar[], int n) {
		double total = 0;

		for (int i = 0; i < n; i++) {
			s.sales[i] = ar[i];
			total += s.sales[i];
		}
		s.average = total / QUARTERS;
		s.max = s.min = ar[0];

		for (int i = 1; i < n; i++) {
			if (ar[i] > s.max)
				s.max = ar[i];
			if (ar[i] < s.min)
				s.min = ar[i];
		}
	}

	void setSales(Sales & s) {
		double total = 0;
		cout << "Incoming sales.\n";
		for (int i = 0; i < QUARTERS; i++) {
			cout << "#" << i + 1 << ": ";
			while (!(cin >> s.sales[i])) {
				cin.clear();
				while (cin.get() != '\n')
					continue;
			}
			total += s.sales[i];
		}
		s.average = total / QUARTERS;

		s.max = s.min = s.sales[0];
		for (int i = 1; i < QUARTERS; i++) {
			if (s.sales[i] > s.max)
				s.max = s.sales[i];
			if (s.sales[i] < s.min)
				s.min = s.sales[i];
		}
	}

	void showSales(const Sales & s) {
		cout << "Sales.\n";
		for (int i = 0; i < QUARTERS; i++)
			cout << "#" << i + 1 << " " << s.sales[i] << endl;
		cout << "average = " << s.average << endl;
		cout << "max = " << s.max << ", "
			<< "min = " << s.min << endl;
	}
}