pacman/exercises/25/pacman_ai/README.md

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# Exercise: PacMan AI

Let's implement a naive AI for PacMan.

## Background: PacMan Moves

At each intersection, check if there is a ghost directly inline with that path. If the path is free of ghosts, you are
allowed to turn there. And if PacMan is moving in a direction, and a ghost enters his path, then pacman will reverse.

For example if pacman is at an intersection and can go either right or up, and there is a ghost in the path going right,
then pacman will go up. Then while pacman is going up, a ghost enters that path, pacman will go back.

You only need to worry about the grid itself and any ghosts on the North/South/East/West axis of PacMan.

## Exercise

1. Implement [PacManAI::pelletClosestToPacman](../../../lib/PacManAI.cpp) and test your implementation with the test
   in [testPacmanAI.cpp](../../../test/testPacmanAI.cpp) called _"Find pellet closest to pacman"_

*Hint*:

```cpp
GridPosition PacManAI::pelletClosestToPacman(GridPosition pacmanGridPosition,
                                             std::vector<GridPosition> & pellets) {
  return {0, 0};
}
```

2. Implement [PacManAI::isValidMove](../../../lib/PacManAI.cpp) and test your implementation with the test
   in [testPacmanAI.cpp](../../../test/testPacmanAI.cpp) called _"Is valid move"_

*Hint*:

```cpp
bool PacManAI::isValidMove(const Move & move) {
  return false;
}
```

3. Implement [PacManAI::optimalDirection](../../../lib/PacManAI.cpp) and test your implementation with the test
   in [testPacmanAI.cpp](../../../test/testPacmanAI.cpp) called _"Is optimal direction"_

*Hint*:

```cpp
Direction PacManAI::optimalDirection(const std::array<Move, 4> & moves) {
  return Direction::NONE;
}
```