while(alive){eat();code();sleep();}

Always take notes, learn from your failures:

• If you can't explain it simply, you don't know it well enough.
• Plan ahead for variable lifespan until it becomes a habit.
• Delete destroys the pointer to object and assigns an invalid address. That invalid address is the wreckage of that destruction. You still have access to crash the program.
• Avoid bare pointers.
• Nobody needs raw pointers where smarts are enough.
• Don't allocate memory as much as possible.
• Avoid returning a local object by reference.
• Don't pass an Object by Value.
• The STL part of the library is generally not meant to be derived from. It uses generic programming, and generally avoids OOP.