2025-11-18 Review Practice

More review exercises covering the fundamentals. Originally from enrichment.

Make a data type Cir to hold a Point called pt and a Double called diam. This represents a circle with center pt and diameter diam.
Make a data type Game to hold a String called name and a list of Cir called ccc.
Write a function that doubles the diameter and leaves the center unchanged.
```
 larger :: Cir -> Cir
```
Find the area of a circle with a given diameter.
```
 area :: Cir -> Double
```
Subtract 0.5 from each y coordinate in the Game.
```
 lowerall :: Game -> Game
```
Find the total area of all circles in the Game.
```
 fullArea :: Game -> Double
```
Two circles overlap if their radii add to more than the distance between their centers.
```
 overlap :: Cir -> Cir -> Bool
```
Find the first circle that overlaps one given circle. If there is no such circle, output Nothing.
```
 touching :: Cir -> [Cir] -> Maybe Cir
 touching given circs = undefined -- fix
```
1. Recursion
2. List comprehension plus something
3. Higher order function (map, fold, filter)