9.24作业
将昨天的My_string类中的所有能重载的运算符全部进行重载
+、[] 、>、<、==、>=、<=、!= 、+=（可以加等一个字符串，也可以加等一个字符）、输入输出(<< 、 >>)
代码如下
MyString.h
#ifndef MYSTRING_H
#define MYSTRING_H
#include <iostream>
#include <cstring>using namespace std;class My_string
{
private:char *ptr; //指向字符数组的指针int size; //字符串的最大容量int len; //字符串当前容量public://无参构造My_string();//有参构造My_string(const char* src);My_string(int num, char value);//拷贝构造My_string(const My_string &other);//拷贝赋值My_string & operator= (const My_string &other);//析构函数~My_string();//判空bool Isvoid();//显示void show();//尾插void push_back(char value);//尾删void pop_back();//at函数实现char &at(int index);//清空函数void clear();//返回C风格字符串char *data();//返回实际长度int get_length();//返回当前最大容量int get_size();//君子函数:二倍扩容bool Add();//自定义 + 运算符重载函数My_string operator+ (const My_string &R);//自定义 [] 运算符重载函数char& operator[] (int index);//自定义 >< == >= <=运算符重载函数bool operator> (My_string &R);bool operator< (My_string &R);bool operator== (My_string &R);bool operator== (My_string &&s);bool operator!= (My_string &R);bool operator>= (My_string &R);bool operator<= (My_string &R);//自定义 += 运算符重载函数My_string operator+= (const My_string &R);My_string operator+= (const My_string &&R);//友元friend ostream & operator<< (ostream &L,const My_string &R);friend istream & operator>> (istream &L,const My_string &R);};//定义全局函数 << >>运算符重载
ostream & operator<< (ostream &L,const My_string &R);
istream & operator>> (istream &L,const My_string &R);
#endif // MYSTRING_HMyString.cpp
#include "MyString.h"My_string::My_string() : size(15), len(0) {ptr = new char[size];ptr[0] = '\0'; // 表示串为空串cout << "无参构造" << endl;
}My_string::My_string(const char* src) : size(15) {ptr = new char[size];strcpy(ptr, src); // 复制字符串len = strlen(src);
// cout << "一个形参的有参构造" << endl;
}My_string::My_string(int num, char value) : size(15), len(num) {if (num > 15) {cout << "超出默认长度" << endl;return;}ptr = new char[size];for (int i = 0; i < num; i++) {ptr[i] = value;}ptr[num] = '\0'; // 确保字符串以'\0'结尾
// cout << "部分形参的有参构造" << endl;
}My_string::My_string(const My_string &other) : size(other.size), len(other.len) {ptr = new char[size];strcpy(ptr, other.ptr); // 复制字符串cout << "拷贝构造" << endl;
}My_string& My_string::operator= (const My_string &other) {if (this != &other) {delete[] ptr; // 释放旧内存size = other.size;len = other.len;ptr = new char[size];strcpy(ptr, other.ptr); // 复制字符串}cout << "拷贝赋值" << endl;return *this;
}My_string::~My_string() {
// cout << ptr << "析构函数" << endl;delete[] ptr;
}bool My_string::Isvoid() {return len == 0;
}void My_string::show() {cout << ptr << endl;
}void My_string::push_back(char value) {if (len < size - 1) {ptr[len++] = value;ptr[len] = '\0'; // 确保字符串以'\0'结尾} else if (Add()) {ptr[len++] = value;ptr[len] = '\0'; // 确保字符串以'\0'结尾}
}void My_string::pop_back() {if (len > 0) {len--;ptr[len] = '\0'; // 确保字符串以'\0'结尾}
}char& My_string::at(int index) {if (index < len) {return ptr[index];} else {cout << "下标越界" << endl;exit(EXIT_FAILURE);}
}void My_string::clear() {len = 0;ptr[0] = '\0'; // 确保字符串以'\0'结尾
}char* My_string::data() {return ptr;
}int My_string::get_length() {return len;
}int My_string::get_size() {return size;
}bool My_string::Add() {if (len == size - 1) {char *p = new char[size * 2];strcpy(p, ptr);delete[] ptr; // 释放旧内存ptr = p;size *= 2; // 更新容量return true;}return false;
}My_string My_string::operator+ (const My_string &R) const{My_string temp;temp.len = len + R.len;temp.size = size + R.size;temp.ptr = new char[temp.size];temp.ptr[0] = '\0'; // 确保以 '\0' 开头strcat(temp.ptr,this->ptr);strcat(temp.ptr,R.ptr);return temp;
}char& My_string::operator[] (int index){return this->ptr[index];
}bool My_string::operator> (My_string &R){return strcmp(this->ptr,R.ptr)>0 ? true:false;
}bool My_string::operator< (My_string &R){return strcmp(R.ptr,this->ptr)>0 ? true:false;
}
bool My_string::operator== (My_string &R){return strcmp(R.ptr,this->ptr)==0 ? true:false;
}
bool My_string::operator== (My_string &&R){return strcmp(R.ptr,this->ptr)==0 ? true:false;
}
bool My_string::operator!= (My_string &R){return strcmp(R.ptr,this->ptr)!=0 ? true:false;
}
bool My_string::operator>= (My_string &R){return strcmp(R.ptr,this->ptr)>=0 ? true:false;
}
bool My_string::operator<= (My_string &R){return strcmp(R.ptr,this->ptr)<=0 ? true:false;
}
My_string My_string::operator+= (const My_string &R){this->len += R.len;this->size += R.size;strcat(this->ptr,R.ptr);return *this;
}
My_string My_string::operator+= (const My_string &&R){this->len += R.len;this->size += R.size;strcat(this->ptr,R.ptr);return *this;
}ostream & operator<< (ostream &L,const My_string &R){L<<R.ptr<<endl;return L;
}istream & operator>> (istream &L,const My_string &R){char buff[1024];L>>buff;if(strlen(buff)<R.size){strcpy(R.ptr,buff);R.len = strlen(buff);}else cout<<"超出大小！"<<endl;return L;
}main.cpp
#include "MyString.h"int main() {My_string s1("hello");My_string s2 = s1 + " world";s2.show();My_string s3 = "nihao";if(s2>s3){cout<<"s2大"<<endl;}else cout<<"s3大"<<endl;if(s1==s3){cout<<"s1==s3"<<endl;}else cout<<"s1!=s3"<<endl;if(s1=="hello"){cout<<"s1==hello"<<endl;}s1 += s3;s1.show();s3 += " world";s3.show();My_string s4;cout<<"请输入一个字符串："<<endl;cin>>s4;cout<<s4;return 0;
}
运行结果
仿照stack类实现my_stack,实现一个栈的操作
代码如下
MyStack.h
#ifndef MYSTACK_H
#define MYSTACK_H
#include <iostream>using namespace std;
class My_stack {
private:static const int MAX_SIZE = 10; // 定义栈的最大容量int data[MAX_SIZE]; // 固定大小的数组int topIndex; // 栈顶索引public:// 构造函数My_stack();// 拷贝构造函数My_stack(const My_stack &other);// 赋值运算符My_stack& operator=(const My_stack &other);// 析构函数~My_stack(){}// 返回栈顶元素int& top();// 返回栈是否为空bool empty() const;// 返回栈的大小int size() const;// 压入元素void push(int value);// 弹出元素void pop();// 交换两个栈的内容void swap(My_stack &other);
};// 全局函数用于交换两个栈
void swap(My_stack &a, My_stack &b);
#endifMyStack.cpp
#include "MyStack.h"
My_stack::My_stack() : topIndex(-1) {}// 拷贝构造函数
My_stack::My_stack(const My_stack &other) : topIndex(other.topIndex) {for (int i = 0; i < topIndex; ++i) {data[i] = other.data[i];}
}// 赋值运算符
My_stack& My_stack::operator=(const My_stack &other) {if (this != &other) {topIndex = other.topIndex; // 更新栈顶索引for (int i = 0; i < topIndex; ++i) {data[i] = other.data[i]; // 复制元素}}return *this;
}// 返回栈顶元素
int& My_stack::top() {if (empty()) {cout<< "栈空！" << endl;exit(EXIT_FAILURE); // 直接退出程序}return data[topIndex - 1];
}// 返回栈是否为空
bool My_stack::empty() const {return topIndex == -1;
}// 返回栈的大小
int My_stack::size() const {return topIndex;
}// 压入元素
void My_stack::push(int value) {if (topIndex >= MAX_SIZE) {cout << "栈满！" << endl;exit(EXIT_FAILURE); // 直接退出程序}data[topIndex++] = value;
}// 弹出元素
void My_stack::pop() {if (empty()) {cout<< "栈空！" << endl;exit(EXIT_FAILURE); // 直接退出程序}--topIndex;
}// 交换两个栈的内容
void My_stack::swap(My_stack &other) {std::swap(topIndex, other.topIndex);for (int i = 0; i < MAX_SIZE; ++i) {std::swap(data[i], other.data[i]);}
}// 全局函数用于交换两个栈
void swap(My_stack &a, My_stack &b) {a.swap(b);
}main.cpp
#include "MyStack.h"int main() {My_stack s;s.push(9);s.push(2);s.push(6);s.push(7);s.push(8);cout << "栈顶元素：" << s.top() << endl;cout << "栈的大小：" << s.size() << endl;s.pop();cout << "栈顶元素：" << s.top() << endl;My_stack s1;s1.push(1);s1.push(2);My_stack s2;s2 = s;swap(s2, s1); // 交换两个栈cout << "交换后的栈顶元素：" << s2.top() << endl;cout << "交换后另一个栈顶元素：" << s1.top() << endl;return 0;
}运行结果
思维导图
