Advertisements
Advertisements
Advertisements
编译环境Visual Studio 2017
// Chapter12.h
#pragma once
#ifndef CHAPTER12_H_
#define CHAPTER12_H_
class Cow {
char name[20];
char * hobby;
double weight;
public:
Cow();
Cow(const char * nm, const char * ho, double wt);
Cow(const Cow & c);
~Cow();
Cow & operator=(const Cow & c);
void ShowCow() const;
};
#endif // !CHAPTER12_H_
// Chapter12.cpp
#include <iostream>
#include <string>
#include <cstring>
#include <cctype>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include "Chapter12.h"
#include "string2.h"
#include "Stock.h"
#include "Stack.h"
#include "Queue.h"
using namespace std;
// practice 1
Cow::Cow()
{
}
Cow::Cow(const char * nm, const char * ho, double wt)
{
strncpy(name, nm, 20);
int ho_length = strlen(ho);
hobby = new char[ho_length + 1];
strncpy(hobby, ho, ho_length);
hobby[ho_length] = '\0';
weight = wt;
}
Cow::Cow(const Cow & c)
{
strncpy(name, c.name, 20);
int ho_length = strlen(c.hobby);
hobby = new char[ho_length + 1];
strncpy(hobby, c.hobby, ho_length);
hobby[ho_length] = '\0';
weight = c.weight;
}
Cow::~Cow()
{
delete[] hobby;
hobby = nullptr;
}
Cow & Cow::operator=(const Cow & c)
{
strncpy(name, c.name, 20);
int ho_length = strlen(c.hobby);
hobby = new char[ho_length + 1];
strncpy(hobby, c.hobby, ho_length);
hobby[ho_length] = '\0';
weight = c.weight;
return *this;
}
void Cow::ShowCow() const
{
cout << "Cow name: " << name << endl;
cout << "Cow hobby: " << hobby << endl;
cout << "Cow weight: " << weight << endl;
}
void p12_1(void)
{
Cow cow1("hehehe", "eat", 123.4);
Cow cow2("heihei", "drink", 321.2);
Cow cow3(cow2);
Cow cow4 = cow1;
cow1.ShowCow();
cow2.ShowCow();
cow3.ShowCow();
cow4.ShowCow();
}
// practice 2
void p12_2(void)
{
String2 s1("and i am a C++ student.");
String2 s2 = "Please enter your name: ";
String2 s3;
cout << s2;
cin >> s3;
s2 = "My name is " + s3;
cout << s2 << ".\n";
s2 = s2 + s1;
s2.Stringup();
cout << "The sting\n" << s2 << "\ncontains " << s2.has('A')
<< " 'A' characters in it.\n";
s1 = "red";
String2 rgb[3] = { String2(s1), String2("green"), String2("blue") };
cout << "Enter the name of a primary color for mixing light: ";
String2 ans;
bool success = false;
while (cin >> ans)
{
ans.Stringlow();
for (int i = 0; i < 3; i++)
{
if (ans == rgb[i])
{
cout << "That's right!\n";
success = true;
break;
}
}
if (success)
{
break;
}
else
{
cout << "Try again!\n";
}
}
cout << "Bye!\n";
return ;
}
// practice 3
const int STKS = 4;
void p12_3(void)
{
Stock stocks[STKS] = {
Stock("NanoSmart", 12, 20.0),
Stock("Boffo Objects", 200, 2.0),
Stock("Monolithic Obelisks", 130, 3.25),
Stock("Fleep Enterprises", 60, 6.5)
};
std::cout << "Stock holdings:\n";
int st;
for (st = 0; st < STKS; st++)
{
std::cout << stocks[st];
}
const Stock * top = &stocks[0];
for (st = 0; st < STKS; st++)
{
top = &top->topval(stocks[st]);
}
std::cout << "\nMost valuable holding:\n";
cout << *top;
return;
}
// practice 4
void p12_4(void)
{
Stack st1(10);
srand(time(0));
for (size_t i = 0; i < 10; i++)
{
if (!st1.push(rand() % 100))
{
cout << "Push error!" << endl;;
}
}
if (!st1.push(0))
{
cout << "Push 0 error!" << endl;
}
Stack st2(st1);
Stack st3 = st1;
// 故意导致pop error
for (size_t i = 0; i < 11; i++)
{
Item item;
cout << "#" << i+1 << ": " << endl;
if (!st1.pop(item))
{
cout << "st1 pop error!" << endl;
}
else
cout << "st1: " << item << endl;
if (!st2.pop(item))
{
cout << "st2 pop error!" << endl;
}
else
cout << "st2: " << item << endl;
if (!st3.pop(item))
{
cout << "st3 pop error!" << endl;
}
else
cout << "st3: " << item << endl;
cout << endl;
}
}
// practice 5
const int MIN_PER_HR = 60;
bool newcustomer(double x)
{
return (std::rand() * x / RAND_MAX < 1);
}
void p12_5(void)
{
using std::cin;
using std::cout;
using std::endl;
using std::ios_base;
std::srand(std::time(0));
cout << "Case Study: Bank of Heather Automatic Teller\n";
cout << "Enter maximun size of queue: ";
int qs;
cin >> qs;
Queue line(qs);
// 直接将测试时间设置为100好了
cout << "Simulation hours: 100" << endl;
int hours = 100;
long cyclelimit = MIN_PER_HR * hours;
cItem temp;
long turnaways = 0;
long customers = 0;
long served = 0;
long sum_line = 0;
int wait_time = 0;
long line_wait = 0;
double avg_wait_time = 0.0;
// 每小时使用人数初始值为15,之后进行+1枚举测试
double perhour = 15;
double min_per_cust;
do {
min_per_cust = MIN_PER_HR / perhour;
turnaways = 0;
customers = 0;
served = 0;
sum_line = 0;
wait_time = 0;
line_wait = 0;
avg_wait_time = 0;
// 需要清空队列
while (!line.isempty())
{
line.dequeue(temp);
}
for (int cycle = 0; cycle < cyclelimit; cycle++)
{
if (newcustomer(min_per_cust))
{
if (line.isfull())
{
turnaways++;
}
else
{
customers++;
temp.set(cycle);
line.enqueue(temp);
}
}
if (wait_time <= 0 && !line.isempty())
{
line.dequeue(temp);
wait_time = temp.ptime();
line_wait += (cycle - temp.when());
served++;
}
if (wait_time > 0)
{
wait_time--;
}
sum_line += line.queuecount();
}
if (customers > 0)
{
cout << "customers accepted: " << customers << endl;
cout << " customers served: " << served << endl;
cout << " turnaways: " << turnaways << endl;
cout << "average queue size: ";
cout.precision(2);
cout.setf(ios_base::fixed, ios_base::floatfield);
cout << (double)sum_line / cyclelimit << endl;
avg_wait_time = (double)line_wait / served;
cout << " average wait time: "
<< avg_wait_time << " minutes\n" << endl;
}
else
cout << "No customers!\n" << endl;;
// 平均等待时间不一定刚好是1,设置在一个区间内
} while ((perhour++) && (avg_wait_time < 0.9) || (avg_wait_time > 1.1));
cout << "When perhour = " << perhour << " , the average wait time"
" will be about 1 minute\n" << endl;
cout << "Done!\n";
return;
}
// practice 6
void p12_6(void)
{
using std::cin;
using std::cout;
using std::endl;
using std::ios_base;
std::srand(std::time(0));
cout << "Case Study: Bank of Heather Automatic Teller\n";
cout << "Enter maximun size of queue: ";
int qs;
cin >> qs;
Queue line1(qs);
Queue line2(qs);
// 直接将测试时间设置为100好了
cout << "Simulation hours: 100" << endl;
int hours = 100;
long cyclelimit = MIN_PER_HR * hours;
cItem temp;
long turnaways = 0;
long customers = 0;
long served = 0;
long sum_line = 0;
int wait_time1 = 0;
int wait_time2 = 0;
int line1_size = 0;
int line2_size = 0;
long line_wait = 0;
double avg_wait_time = 0.0;
// 每小时使用人数初始值为15,之后进行+1枚举测试
double perhour = 15;
double min_per_cust;
do {
min_per_cust = MIN_PER_HR / perhour;
turnaways = 0;
customers = 0;
served = 0;
sum_line = 0;
wait_time1 = 0;
wait_time2 = 0;
line1_size = 0;
line2_size = 0;
line_wait = 0;
avg_wait_time = 0;
// 需要清空队列
while (!line1.isempty())
{
line1.dequeue(temp);
}
while (!line2.isempty())
{
line2.dequeue(temp);
}
for (int cycle = 0; cycle < cyclelimit; cycle++)
{
if (newcustomer(min_per_cust))
{
if (line1.isfull() && line2.isfull())
{
turnaways++;
}
else if (line1_size > line2_size)
{
customers++;
temp.set(cycle);
line2.enqueue(temp);
line2_size++;
}
else
{
customers++;
temp.set(cycle);
line1.enqueue(temp);
line1_size++;
}
}
if (wait_time1 <= 0 && !line1.isempty())
{
line1.dequeue(temp);
line1_size--;
wait_time1 = temp.ptime();
line_wait += (cycle - temp.when());
served++;
}
if (wait_time2 <=0 && !line2.isempty())
{
line2.dequeue(temp);
line2_size--;
wait_time2 = temp.ptime();
line_wait += (cycle - temp.when());
served++;
}
if (wait_time1 > 0)
{
wait_time1--;
}
if (wait_time2 > 0)
{
wait_time2--;
}
sum_line += line1.queuecount();
sum_line += line2.queuecount();
}
if (customers > 0)
{
cout << "customers accepted: " << customers << endl;
cout << " customers served: " << served << endl;
cout << " turnaways: " << turnaways << endl;
cout << "average queue size: ";
cout.precision(2);
cout.setf(ios_base::fixed, ios_base::floatfield);
cout << (double)sum_line / cyclelimit << endl;
avg_wait_time = (double)line_wait / served;
cout << " average wait time: "
<< avg_wait_time << " minutes\n" << endl;;
}
else
cout << "No customers!\n" << endl;
// 平均等待时间不一定刚好是1,设置在一个区间内
} while ((perhour++) && (avg_wait_time < 0.9) || (avg_wait_time > 1.1));
cout << "When perhour = " << perhour << " , the average wait time"
" will be about 1 minute\n" << endl;
cout << "Done!\n";
return;
}
int main(int argc, char **argv)
{
p12_6();
while (cin.get());
}
// Queue.h
#pragma once
class Customer
{
private:
long arrive;
int processtime;
public:
Customer() { arrive = processtime = 0; }
void set(long when);
long when() const { return arrive; }
int ptime() const { return processtime; }
};
typedef Customer cItem;
class Queue
{
private:
struct Node { cItem item; struct Node * next; };
enum {Q_SIZE = 10};
Node * front;
Node * rear;
int items;
const int qsize;
Queue(const Queue & q) : qsize(0) {}
Queue & operator=(const Queue & q) { return *this; }
public:
Queue(int qs = Q_SIZE);
~Queue();
bool isempty() const;
bool isfull() const;
int queuecount() const;
bool enqueue(const cItem & item);
bool dequeue(cItem & item);
};
// Queue.cpp
#include "Queue.h"
#include <cstdlib>
Queue::Queue(int qs) : qsize(qs)
{
front = rear = NULL;
items = 0;
}
Queue::~Queue()
{
Node * temp;
while (front != NULL)
{
temp = front;
front = front->next;
delete temp;
}
}
bool Queue::isempty() const
{
return items == 0;
}
bool Queue::isfull() const
{
return items == qsize;
}
int Queue::queuecount() const
{
return items;
}
bool Queue::enqueue(const cItem & item)
{
if (isfull())
{
return false;
}
Node * add = new Node;
add->item = item;
add->next = NULL;
items++;
if (front == NULL)
{
front = add;
}
else
rear->next = add;
rear = add;
return true;
}
bool Queue::dequeue(cItem & item)
{
if (front == NULL)
{
return false;
}
item = front->item;
items--;
Node * temp = front;
front = front->next;
delete temp;
if (items == 0)
{
rear = NULL;
}
return true;
}
void Customer::set(long when)
{
processtime = std::rand() % 3 + 1;
arrive = when;
}
// Stack.h
#pragma once
typedef unsigned long Item;
class Stack
{
private:
enum {MAX = 10};
Item * pitems;
int size;
int top;
public:
Stack(int n = MAX);
Stack(const Stack & st);
~Stack();
bool isempty() const;
bool isfull() const;
bool push(const Item & item);
bool pop(Item & item);
Stack & operator=(const Stack & st);
};
// Stack.cpp
#include "Stack.h"
#include <iostream>
Stack::Stack(int n)
{
pitems = new Item[n];
size = n;
top = 0;
}
Stack::Stack(const Stack & st)
{
size = st.size;
pitems = new Item[size];
top = st.top;
for (int i = 0; i < top; i++)
{
pitems[i] = st.pitems[i];
}
}
Stack::~Stack()
{
delete[] pitems;
pitems = nullptr;
}
bool Stack::isempty() const
{
return top == 0;
}
bool Stack::isfull() const
{
return top == size;
}
bool Stack::push(const Item & item)
{
if (isfull())
{
return false;
}
pitems[top++] = item;
return true;
}
bool Stack::pop(Item & item)
{
if (isempty())
{
return false;
}
item = pitems[--top];
return true;
}
Stack & Stack::operator=(const Stack & st)
{
size = st.size;
pitems = new Item[size];
top = st.top;
for (int i = 0; i < top; i++)
{
pitems[i] = st.pitems[i];
}
return *this;
}
// Stock.h
#pragma once
#include <iostream>
class Stock
{
private:
char * company;
int shares;
double share_val;
double total_val;
void set_tot() { total_val = shares * share_val; }
public:
Stock();
Stock(const char * co, long n = 0, double pr = 0.0);
~Stock();
void buy(long num, double price);
void sell(long num, double price);
void update(double price);
void show() const;
friend std::ostream & operator<<(std::ostream & os, const Stock & st);
const Stock & topval(const Stock & s) const;
};
// Stock.cpp
#include "Stock.h"
#include <cstring>
Stock::Stock()
{
int len = std::strlen("no name");
company = new char[len + 1];
std::strcpy(company, "no name");
company[len] = '\0';
shares = 0;
share_val = 0.0;
total_val = 0.0;
}
Stock::Stock(const char * co, long n, double pr)
{
int len = std::strlen(co);
company = new char[len + 1];
std::strcpy(company, co);
if (n < 0)
{
std::cout << "Number of shares can't be negative; "
<< company << " shares set to n.\n";
shares = 0;
}
else
shares = n;
share_val = pr;
set_tot();
}
Stock::~Stock()
{
delete[] company;
company = nullptr;
}
void Stock::buy(long num, double price)
{
if (num < 0)
{
std::cout << "Number of shares purchased can't be negative. "
<< "Transaction is aborted.\n";
}
else
{
shares += num;
share_val = price;
set_tot();
}
}
void Stock::sell(long num, double price)
{
using std::cout;
if (num < 0)
{
cout << "Number of shares sold can't be negative. "
<< "Transaction is aborted.\n";
}
else if (num > shares)
{
cout << "You can't sell more than you have! "
<< "Transaction is aborted.\n";
}
else
{
shares -= num;
share_val = price;
set_tot();
}
}
void Stock::update(double price)
{
share_val = price;
set_tot();
}
void Stock::show() const
{
using std::cout;
using std::ios_base;
ios_base::fmtflags orig =
cout.setf(ios_base::fixed, ios_base::floatfield);
std::streamsize prec = cout.precision(3);
cout << "Company: " << company
<< " Shares: " << shares << '\n';
cout << "Share Price: $" << share_val;
cout.precision(2);
cout << " Total Worth: $" << total_val << '\n';
cout.setf(orig, ios_base::floatfield);
cout.precision(prec);
}
std::ostream & operator<<(std::ostream & os, const Stock & st)
{
using std::ios_base;
ios_base::fmtflags orig =
os.setf(ios_base::fixed, ios_base::floatfield);
std::streamsize prec = os.precision(3);
os << "Company: " << st.company
<< " Shares: " << st.shares << '\n';
os << " Share Price: $" << st.share_val;
os.precision(2);
os << " Total Worth: $" << st.total_val << '\n';
os.setf(orig, ios_base::floatfield);
os.precision(prec);
return os;
}
const Stock & Stock::topval(const Stock & s) const
{
if (s.total_val > total_val)
{
return s;
}
else
return *this;
}
// string2.h
#pragma once
#ifndef STRING2_H_
#define STRING2_H_
#include <iostream>
using std::ostream;
using std::istream;
class String2
{
private:
char * str;
int len;
static int num_strings;
static const int CINLIM = 80;
public:
String2(const char * s);
String2();
String2(const String2 &);
~String2();
int length() const { return len; }
String2 & operator=(const String2 &);
String2 & operator=(const char *);
char & operator[](int i);
const char & operator[](int i) const;
friend bool operator<(const String2 &st, const String2 &st2);
friend bool operator>(const String2 &st, const String2 &st2);
friend bool operator==(const String2 &st, const String2 &st2);
friend ostream & operator<<(ostream & os, const String2 &st);
friend istream & operator>>(istream & is, String2 &st);
static int HowMany();
String2 operator+(const String2 &) const;
String2 operator+(const char *) const;
friend String2 operator+(const char *, const String2 &);
void Stringlow();
void Stringup();
int has(char);
};
#endif // !STRING2_H_
// string2.cpp
#include <cstring>
#include "string2.h"
using std::cin;
using std::cout;
int String2::num_strings = 0;
int String2::HowMany()
{
return num_strings;
}
String2::String2(const char * s)
{
len = std::strlen(s);
str = new char[len + 1];
std::strcpy(str, s);
num_strings++;
}
String2::String2()
{
len = 4;
str = new char[1];
str[0] = '\0';
num_strings++;
}
String2::String2(const String2 & st)
{
num_strings++;
len = st.len;
str = new char[len + 1];
std::strcpy(str, st.str);
}
String2::~String2()
{
--num_strings;
delete[] str;
}
String2 & String2::operator=(const String2 & st)
{
if (this == &st)
{
return *this;
}
delete[] str;
len = st.len;
str = new char[len + 1];
std::strcpy(str, st.str);
return *this;
}
String2 & String2::operator=(const char * s)
{
delete[] str;
len = std::strlen(s);
str = new char[len + 1];
std::strcpy(str, s);
return *this;
}
char & String2::operator[](int i)
{
return str[i];
}
const char & String2::operator[](int i) const
{
return str[i];
}
bool operator<(const String2 & st, const String2 & st2)
{
return(std::strcmp(st.str, st2.str) < 0);
}
bool operator>(const String2 & st, const String2 & st2)
{
return(std::strcmp(st.str, st2.str) > 0);
}
bool operator==(const String2 & st, const String2 & st2)
{
return(std::strcmp(st.str, st2.str) == 0);
}
ostream & operator<<(ostream & os, const String2 & st)
{
os << st.str;
return os;
}
istream & operator>>(istream & is, String2 & st)
{
char temp[String2::CINLIM];
is.get(temp, String2::CINLIM);
if (is)
{
st = temp;
}
while (is && is.get() != '\n')
{
continue;
}
return is;
}
String2 String2::operator+(const String2 & st) const
{
int total_len = len + st.len;
char *temp = new char[total_len + 1];
std::strcpy(temp, str);
std::strcpy(temp + len, st.str);
temp[total_len] = '\0';
return String2(temp);
}
String2 String2::operator+(const char * s) const
{
int total_len = len + strlen(s);
char *temp = new char[total_len + 1];
std::strcpy(temp, str);
std::strcpy(temp + len, s);
temp[total_len] = '\0';
return String2(temp);
}
String2 operator+(const char * s, const String2 & st)
{
return String2(s) + st;
}
void String2::Stringlow()
{
for (int i = 0; i < len + 1; i++)
{
str[i] = tolower(str[i]);
}
}
void String2::Stringup()
{
for (int i = 0; i < len + 1; i++)
{
str[i] = toupper(str[i]);
}
}
int String2::has(char c)
{
int same = 0;
for (int i = 0; i < len; i++)
{
if (str[i] == c)
{
same++;
}
}
return same;
}
此文文博主原创文章,转载请注明出处
Advertisements
Advertisements
Advertisements
你这上面的赋值运算符重载是不是写的有点问题?不需要释放原有内存空间吗?我看的是practice4,其他我就没看了。