exercism/cpp/pacman-rules

Pacman Rules

Welcome to Pacman Rules on Exercism's C++ Track. If you need help running the tests or submitting your code, check out HELP.md. If you get stuck on the exercise, check out HINTS.md, but try and solve it without using those first :)

Introduction

Booleans in C++ are represented by the bool type. A bool is either true or false.

Logical Operators

C++ supports three boolean operators: ! (NOT), && (AND), and || (OR). You can also use the alternative versions not, and, and or.

true || false // => true
true && false // => false
!true // => false
not false // => true

Precedence

The three boolean operators each have different operator precedence. As a consequence, they are evaluated in this order: ! first, && second, and finally ||. If you want to force a different ordering, you can enclose a boolean expression in parentheses (ie. ()), as the parentheses have even higher operator precedence.

!true && false   // => false
!(true and false) // => true

## Conversion

If you use `true` or `false` in a place where a number is expected, they will be converted to  `1` and `0` respectively.
If you use a number in a Boolean operation, everything except `0` is treated as `true` - even negative values.

```cpp
!true && 0.0   // => false
true + true + false // => 2
```

Instructions

In this exercise, you need to translate some rules from the classic game Pac-Man into C++ functions.

You have four rules to translate, all related to the game states.

Don't worry about how the arguments are derived, just focus on combining the arguments to return the intended result.

1. Define if Pac-Man eats a ghost

Define the can_eat_ghost function that takes two arguments (if Pac-Man has a power pellet active and if Pac-Man is touching a ghost) and returns a boolean value if Pac-Man is able to eat the ghost. The function should return true only if Pac-Man has a power pellet active and is touching a ghost.

can_eat_ghost(false, true);
// => false

2. Define if Pac-Man scores

Define the scored function that takes two arguments (if Pac-Man is touching a power pellet and if Pac-Man is touching a dot) and returns a boolean value if Pac-Man scored. The function should return true if Pac-Man is touching a power pellet or a dot.

scored(true, true);
// => true

3. Define if Pac-Man loses

Define the lost function that takes two arguments (if Pac-Man has a power pellet active and if Pac-Man is touching a ghost) and returns a boolean value if Pac-Man loses. The function should return true if Pac-Man is touching a ghost and does not have a power pellet active.

lost(false, true);
// => true

4. Define if Pac-Man wins

Define the won function that takes three arguments (if Pac-Man has eaten all of the dots, if Pac-Man has a power pellet active, and if Pac-Man is touching a ghost) and returns a boolean value if Pac-Man wins. The function should return true if Pac-Man has eaten all of the dots and has not lost based on the arguments defined in part 3.

won(false, true, false);
// => false

Source

Created by

• @vaeng