PI Team π ❷

#include <iostream> using namespace std; class List { public: ~List() { cout << "List destructor" << endl; } }; class ArrayList : public List { public: ~ArrayList() { cout << "ArrayList destructor" << endl; } }; int main() { List* ptr = new ArrayList(); delete ptr; return 0; }

Complex ptr=&a;

Complex *ptr=&a;

Complex ptrN=new Complex;

Complex *ptrN=new Complex;

Complex ptrArray=new Complex[10];

Complex *ptrArray=new Complex[10];

f x{1,2}; f &b=x;

#include <iostream> using namespace std; struct f{ int a,b; }; int main() { f x{1,2}; f &b=x; if(&b==&x)cout<<"Equal"<<endl; else cout<<"Not Equal"<<endl; return 0; }

struct f{ int a,b; }; int main() { f x{1,2}; f &b=x; b.a=10; cout<<x.a<<endl; return 0; }

Record r[4] = {{10, 1}, {20, 2}, {30, 3}, {40, 4}}; f.write((char*)r, sizeof(r));

f.seekg(-2 * (long)sizeof(Record), ios::end); cout << f.tellg() << " ";

ملاحظة : العناصر مخزنة كالاتي اول عنصر من 0 الى 7 الثاني من 8 الى 15 الثالث : من 16 الى 23 الرابع من 24 الى 31

Record temp; f.read((char*)&temp, sizeof(Record));

f.seekg(-(long)sizeof(Record), ios::cur); f.seekg(-(long)sizeof(Record), ios::cur);

f.read((char*)&temp, sizeof(Record));

20 2

cout << temp.id << " " << temp.val << " " << f.tellg() << endl;

#include <iostream> #include <fstream> using namespace std; struct Record { int id; int val; }; int main() { fstream f("rec.bin", ios::binary | ios::out | ios::in | ios::trunc); Record r[4] = {{10, 1}, {20, 2}, {30, 3}, {40, 4}}; f.write((char*)r, sizeof(r)); f.seekg(-2 * (long)sizeof(Record), ios::end); cout << f.tellg() << " "; Record temp; f.read((char*)&temp, sizeof(Record)); f.seekg(-(long)sizeof(Record), ios::cur); f.seekg(-(long)sizeof(Record), ios::cur); f.read((char*)&temp, sizeof(Record)); cout << temp.id << " " << temp.val << " " << f.tellg() << endl; return 0; }

Student arr[3] = {{1, 80}, {2, 90}, {3, 100}}; f.write((char*)arr, sizeof(arr));

1 80 2 90 3 100

f.seekp(sizeof(Student));

Student temp{4, 95}; f.write((char*)&temp, sizeof(Student));

1 80 4 95 3 100

f.seekg(0, ios::end); int count = f.tellg() / sizeof(Student);

f.seekg(0, ios::end);

f.seekg(sizeof(Student), ios::beg);

Student st2; f.read((char*)&st2, sizeof(Student));

1 80 4 95 3 100

#include <iostream> #include <fstream> using namespace std; struct Student { int id; int mark; }; int main() { fstream f("st.bin", ios::binary | ios::out | ios::in | ios::trunc); Student arr[3] = {{1, 80}, {2, 90}, {3, 100}}; f.write((char*)arr, sizeof(arr)); f.seekp(sizeof(Student)); Student temp{4, 95}; f.write((char*)&temp, sizeof(Student)); f.seekg(0, ios::end); int count = f.tellg() / sizeof(Student); f.seekg(sizeof(Student), ios::beg); Student st2; f.read((char*)&st2, sizeof(Student)); cout << count << " " << st2.id << " " << st2.mark << endl; return 0; }

fstream f("pi.bin", ios::binary | ios::out | ios::in | ios::trunc);

10 20

10 20 30 40

10 20 50 60

#include <iostream> #include <fstream> using namespace std; struct Point { int x; int y; }; // sizeof(Point) = 8 bytes int main() { fstream f("pi.bin", ios::binary | ios::out | ios::in | ios::trunc); Point p1{10, 20}, p2{30, 40}, p3{50, 60}; f.write((char*)&p1, sizeof(Point)); f.write((char*)&p2, sizeof(Point)); f.seekp(-8, ios::cur); f.write((char*)&p3, sizeof(Point)); Point res; f.seekg(0, ios::beg); f.read((char*)&res, sizeof(Point)); f.read((char*)&res, sizeof(Point)); cout << res.x << " " << res.y << " " << f.tellg() << endl; return 0; }

عنا p1=2* لانو عم يأشر على x وعنا p2=3* لانو عم يأشر على y واخر شي p3=3* لانو هوي عم يأشر على المؤشر p2 وp2 عم يأشر على y

Text(p1, z, p3) بطريقة ثانية Text(2,4,3

while(!in.eof()){ in>>x>>y; cout<<x<<' '<<y<<endl; }