Abstract Operation

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

class Operation {
public:
   // your code here: declare pure virtual function apply
   virtual int apply(int x) const = 0;
};

class SquareOp : public Operation {
public:
   int apply(int x) const override {
       return x * x;
   }
};

class CubeOp : public Operation {
public:
   int apply(int x) const override {
       return x * x * x;
   }
};

int main() {
   int n;
   string opName;
   cin >> n >> opName;
   Operation* op = nullptr;
   if (opName == "square") {
       op = new SquareOp();
   } else if (opName == "cube") {
       op = new CubeOp();
   }
   if (op) {
       cout << op->apply(n);
       delete op;
   }
   return 0;
}