Informatika3-2024/Megoldasok5

Megoldások

Csak azoknak a feladatoknak lesznek itt a megoldásai amiket megbeszéltünk gyakorlaton. A többi feladat tökéletes ZH-ra gyakorlásnak!

Téglalap

#include<iostream>
 
using namespace std;
 
class Rectangle {
private:
  float a;
  float b;
public:
  Rectangle();
  Rectangle(float a, float b);
  Rectangle(const Rectangle& other);
 
  float area();
  float perimeter();
 
  void scale(float n);
 
  ~Rectangle();
};
 
Rectangle::Rectangle() {
  this->a = 0;
  this->b = 0;
}
 
Rectangle::Rectangle(float a, float b) {
  this->a = a;
  this->b = b;
}
 
Rectangle::Rectangle(const Rectangle& other) {
  this->a = other.a;
  this->b = other.b;
}
 
float Rectangle::area() {
  return a * b;
}
 
float Rectangle::perimeter() {
  return 2 * (a + b);
}
 
void Rectangle::scale(float n) {
  a = a * n;
  b = b * n;
}
 
Rectangle::~Rectangle() {
}
 
int main(void) {
  Rectangle x = Rectangle();
  //Rectangle x;
  //Rectangle x();
  Rectangle y = Rectangle(5,4);
  //Rectangle y(5,4);
  Rectangle z = Rectangle(y);
  //Rectangle z(y);
 
  cout << y.area() << endl;
  cout << y.perimeter() << endl;
 
  z.scale(2);
 
  cout << y.area() << endl;
  cout << y.perimeter() << endl;
  cout << z.area() << endl;
  cout << z.perimeter() << endl;
 
  return 0;
}

String osztály

(Ezt a feladatot nem fejeztük be teljesen.)

#include<iostream>
 
using namespace std;
 
class String {
private:
  char *str;
  int length;
  int c_string_length(const char* s);
public:
  String();
  String(const char* s);
  String(const String& other);
 
  //void print();
  //int getLength();
 
  //String concat(String other);
 
  //~String();
};
 
int String::c_string_length(const char* s) {
  int i;
  for(i = 0; s[i] != '\0'; i++) {}
  return i;
}
 
String::String() {
  str = new char[1];
  str[0] = '\0';
  length = 0;
}
 
String::String(const char* s) {
  length = c_string_length(s);
  str = new char[length + 1];
  for(int i = 0; s[i] != '\0'; i++) {
    str[i] = s[i];
  }
  str[length] = '\0';
}
 
String::String(const String& other) {
  this->length = other.length;
  str = new char[this->length + 1];
  for(int i = 0; other.str[i] != '\0'; i++) {
    this->str[i] = other.str[i];
  }
  this->str[this->length] = '\0';
}
 
int main(void) {
  String a;
  String b("batman");
  String c(b);
  return 0;
}