Base and Derived

Lab C++ Intermediate 20 points

Write class Animal with a name and a virtual string sound() const returning ..., and Dog and Cat overriding it. Read animals and print NAME says SOUND through an Animal&.

Input

n, then lines dog|cat|animal NAME.

Output

n lines.

Example

Input

3
dog Rex
cat Tom
animal Blob

Output

Rex says woof
Tom says meow
Blob says ...

Sample input available Sample output available

Editor

C++

Hints

virtual lets the call pick the derived version at runtime.

Base classes with virtual functions need a virtual destructor.

Solution explanation

using Animal::Animal; inherits the base constructor; override asks the compiler to check you really override.

Show solution

#include <iostream>
#include <memory>
#include <string>
#include <vector>
using namespace std;

class Animal {
public:
    explicit Animal(string name) : name_(name) {}
    virtual ~Animal() = default;
    virtual string sound() const { return "..."; }
    const string &name() const { return name_; }

private:
    string name_;
};

class Dog : public Animal {
public:
    using Animal::Animal;
    string sound() const override { return "woof"; }
};

class Cat : public Animal {
public:
    using Animal::Animal;
    string sound() const override { return "meow"; }
};

void describe(const Animal &a) { cout << a.name() << " says " << a.sound() << "\n"; }

int main() {
    int n;
    cin >> n;
    vector<unique_ptr<Animal>> zoo;
    for (int i = 0; i < n; i++) {
        string kind, name;
        cin >> kind >> name;
        if (kind == "dog") zoo.push_back(make_unique<Dog>(name));
        else if (kind == "cat") zoo.push_back(make_unique<Cat>(name));
        else zoo.push_back(make_unique<Animal>(name));
    }
    for (const auto &a : zoo) describe(*a);
    return 0;
}

Output

Answer