Instructions

This exercise takes you to the world of Troy. The lives of its people are full of wonder and magic. Many humans in Troy possess powers, that are used frequently in their daily lives. Powers are used to re-shape the world or influence Troy's fauna and other people. Magic also manifests in unique artifacts, that are highly sought after by adventurers, artisans and sages.

In this exercise you are going to write code to model the humans of Troy, their possessed artifacts and power interactions.

You have six tasks. The first one is related to creating a human, the other five are about handling powers and artifacts.

1. Bring humans to the world of Troy

For your model of Troy, humans are the most important feature. Your model human should be able to possess a unique artifact. They should also have the ability to manifest a power. These powers might affect other humans, so you also want to model if a human is influenced by some other power.

You are provided with basic implementations of artifact and power structs. Implement a human struct (or class) that has a smart-pointer to an artifact member variable named possession. Each artifact can only be possessed by a single human at any given time.

A human must have two additional member variables. One holds their own_power and the other is a power they are influenced_by. Both own_power and influenced_by are smart-pointers to powers. Each power might be owned by a single human, but also influence other humans at the same time.

By default, humans are born without any artifact and neither own any powers nor are they influenced by them.

2. Bring Artifacts into Troy

Your model is boring without the interaction of its parts. You want to create unique artifacts and give them to certain humans.

Define the function give_new_artifact which returns nothing but takes a reference to a human and a string. With the string it should define a new artifact object and set the possession pointer of the human accordingly. The function should not return anything.

3. Make items tradeable

The world of Troy is all about interaction. You want people to make trades by exchanging their possessions.

Write a function exchange_artifacts that returns nothing but takes two artifact smart-pointers to exchange the items. Remember, that you cannot copy a unique_ptr. This includes the usage in function parameters. Use a reference to the unique_ptr instead.

4. Give Power to the People

The most exciting feature of Troy are the special powers that people might wield. Some can smelt iron with their thoughts, while others can heal every wound instantly at nighttime.

Define the function manifest_power which returns nothing but takes a reference to a human and a string. With the string it should define a new power object and set the own_power pointer of the human accordingly. The function should not return anything.

5. Use the Power

What use are the greatest powers, if you cannot use them. Your model concentrates on humans, so you want to track the influence of powers.

Write a void function use_power that takes two references to humans. The first human is the caster and the second represents the target. The target's influenced_by pointer should be pointed to the power of the caster.

For simplicity, humans can only be influenced by a single power. This power stays in place even if the caster does not exist any longer.

6. Keep watch on the power's intensity

Certain powers lose their potency or trigger certain effects in your simulation when they are applied to several humans. You want to track the number of people who are connected to each power.

Define the function power_intensity, that takes a human and returns the intensity of their power as an int. If the person has no power, the return value should be 0. Otherwise the intensity should reflect the caster and all currently influenced people.