写一个三角形类，拥有私有成员 a,b,c 三条边 写好构造函数初始化 abc 以及 abc 的set get 接口 再写一个等腰三角形类，继承自三角形类 1：写好构造函数，初始化三条边 2：要求无论如何，等腰三角形类对象，总是等腰的 再写一个等边三角形类，继承自等腰三角形类 1：写好构造函数，初始化三条边 2：要求无论如何，等腰三角形类对象，总是等边

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sstream>
#include <vector>
#include <memory>using namespace std;                 class ABC
{
private:int a;int b;int c;
public:ABC(int a=0,int b=0,int c=0):a(a),b(b),c(c){}void seta(int l){a=l;}void setb(int l){b=l;}void setc(int l){c=l;}int geta(){return a;}int getb(){return b;}int getc(){return c;}
};class ABB:public ABC
{
public:ABB(int a=0,int bb=0):ABC(a,bb,bb){}void seta(int a){ABC::seta(a);ABC::setb(a);}void setb(int b){ABC::seta(b);ABC::setb(b);}
};
class AAA:public ABC
{AAA(int aaa=0):ABC(aaa,aaa,aaa){}void seta(int a){ABC::seta(a);ABC::setb(a);ABC::setc(a);}
};
int main(int argc,const char** argv)
{ABB d;d.seta(4);d.setb(5);d.setc(6);AAA e;e.seta(7);return 0;
}

编写一个长方形类， 私有成员 a,b 构造函数初始化 set get 接口 编写一个正方形类，继承自长方形类 构造函数初始化 无论如何，正方形类对象总是正方形的

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sstream>
#include <vector>
#include <memory>using namespace std;                 class AABB{
private:int a;int b;
public:AABB(int a=0,int b=0):a(a),b(b){};void setA(int l){a = l;}void setB(int l){b = l;}int getA(){return a;}int getB(){return b;}
};class AA:public AABB{
public:AA() : AABB(0,0){}AA(int a):AABB(a,a){}void setA(int a){AABB::setA(a);AABB::setB(a);}void setB(int b){AABB::setA(b);AABB::setB(b);}
};int main(int argc,const char** argv){AA a1;a1.setA(3);a1.setB(4);}

封装消息队列 class Msg{ key_t key int id; int channel } 实现以下功能 Msg m("文件名") m[1].send("数据"),将数据发送到1号频道中 string str = m[1].recv(int size) 从1号频道中读取消息，并且返回 把 send 改成 operator<< ,recv 改成 operator>> 实现效果: m[1] << "helloworld" 将 "helloworld" 写入消息队列的1号频道中 m[1] >> str 读取消息队列中1频道中的消息，存入 str 中

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sstream>
#include <vector>
#include <memory>
#include <sys/ipc.h>
#include <sys/msg.h>using namespace std;class Msg {
private:key_t key;int id;int channel;struct msgbuf {long channel;char text[512];};public:Msg(const string& filename = "") {key = ftok(filename.data(), 1);id = msgget(key, IPC_CREAT | 0666);}~Msg() {msgctl(id, IPC_RMID, 0);}void send(const string& str) {msgbuf buf = {0};strcpy(buf.text, str.data());buf.channel = channel;msgsnd(id, &buf, strlen(buf.text) + 1, 0);}string recv(int size = 512) {msgbuf buf = {0};msgrcv(id, &buf, size, channel, 0);string str = buf.text;return str;}friend Msg& operator<<(Msg& msg, const string& str);friend Msg& operator>>(Msg& msg, string& str);Msg& operator[](int channel) {this->channel = channel;return *this;}
};Msg& operator<<(Msg& msg, const string& str) {msg.send(str);return msg;
}Msg& operator>>(Msg& msg, string& str) {str = msg.recv();return msg;
}int main(int argc, const char** argv) {return 0;
}

封装信号灯集 class Sem{ key_t key int id; int index } 实现以下功能 Sem s(参数x，参数y):创建信号灯集，信号灯集中存在 x 个信号量，并且将所有信号量初始化为 y s[1].init(10):手动初始化信号灯集中的第1个信号量，初始化成 10 s[1] + 1 让信号灯集中的第1个信号量的值 +1 s[1].operator+(1) s[1] - 1 让信号灯集中的第1个信号量的值 -1 追加 operator ++ 功能，即解锁一次 以及 operator-- 功能， 即上锁一次

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sstream>
#include <vector>
#include <memory>
#include <sys/ipc.h>
#include <sys/sem.h>using namespace std;class Sem {
private:key_t key;int id;int index;public:Sem(const string& filename = "", int n, int val) {key = ftok(filename.data(), 1);id = semget(key, n, IPC_CREAT | 0666);for (int i = 0; i < n; i++) {semctl(id, i, SETVAL, val);}}~Sem() {semctl(id, 0, IPC_RMID);}friend Sem& operator+(const Sem& l, int val);friend Sem& operator-(const Sem& l, int val);friend Sem& operator++(Sem& l);friend Sem& operator--(Sem& l);friend Sem& operator[](Sem& l, int index);
};Sem& operator+(Sem& l, int val) {sembuf buf = {0};buf.sem_num = l.index;buf.sem_op = abs(val);buf.sem_flg = SEM_UNDO;semop(l.id, &buf, 1);return l;
}Sem& operator-(Sem& l, int val) {sembuf buf = {0};buf.sem_num = l.index;buf.sem_op = -abs(val);buf.sem_flg = SEM_UNDO;semop(l.id, &buf, 1);return l;
}Sem& operator++(Sem& l) {sembuf buf = {0};buf.sem_num = l.index;buf.sem_op = 1;buf.sem_flg = SEM_UNDO;semop(l.id, &buf, 1);return l;
}Sem& operator--(Sem& l) {sembuf buf = {0};buf.sem_num = l.index;buf.sem_op = -1;buf.sem_flg = SEM_UNDO;semop(l.id, &buf, 1);return l;
}
Sem& operator[](const Sem& l,int index){l.index = index;return l;
}
int main(int argc, const char** argv) {return 0;
}