closures

- try to implement a quick and dirty solution for listing 13-1 myself

closures/src/main.rs

@@ -0,0 +1,162 @@
+// giveaway tshirts to users
+// if someone has a favorite colour they get that
+// else they get whatever colour we currently have the most of
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Ord, PartialOrd)]
+enum ShirtColor {
+    Red,
+    Blue,
+    Green,
+}
+
+#[derive(Debug)]
+struct Inventory {
+    shirts: Vec<ShirtColor>,
+}
+
+#[derive(Debug)]
+struct User {
+    shirt_preference: Option<ShirtColor>,
+}
+
+impl Inventory {
+    fn giveaway(current_inventory: &mut Self, user: &User) -> ShirtColor {
+        let pref = user.shirt_preference;
+        if pref == None {
+            let current_max = Self::current_max(current_inventory);
+            Self::update_inventory(current_inventory, current_max);
+            return current_max;
+        } else {
+            Self::update_inventory(current_inventory, pref.unwrap());
+            return pref.unwrap();
+        }
+    }
+
+    fn update_inventory(current_inventory: &mut Self, current_max: ShirtColor) {
+        let mut temp_inventory = current_inventory.shirts.clone();
+        temp_inventory.sort();
+
+        let mut i = 0;
+        for color in temp_inventory {
+            if color == current_max {
+                current_inventory.shirts.swap_remove(i);
+                return;
+            }
+            i += 1;
+        }
+    }
+
+    fn current_max(current_inventory: &mut Self) -> ShirtColor {
+        let mut green = 0;
+        let mut blue = 0;
+        let mut red = 0;
+
+        let tmp_inventory = current_inventory.shirts.clone();
+        for color in tmp_inventory {
+            match color {
+                ShirtColor::Red => red += 1,
+                ShirtColor::Blue => blue += 1,
+                ShirtColor::Green => green += 1,
+            }
+        }
+
+        if blue > green && blue > red {
+            return ShirtColor::Blue;
+        };
+
+        if green > blue && green > red {
+            return ShirtColor::Green;
+        };
+
+        if red > blue && red > green {
+            return ShirtColor::Red;
+        };
+
+        if blue == red && blue == green {
+            return ShirtColor::Blue;
+        };
+
+        if blue == red && blue < green {
+            return ShirtColor::Green;
+        };
+
+        if blue == red && blue > green {
+            return ShirtColor::Blue;
+        };
+
+        if green == blue && green > red {
+            return ShirtColor::Blue;
+        };
+
+        if green == blue && green < red {
+            return ShirtColor::Red;
+        };
+
+        if red == green && green > blue {
+            return ShirtColor::Green;
+        };
+
+        if red == green && green < blue {
+            return ShirtColor::Blue;
+        } else {
+            return ShirtColor::Green;
+        }
+    }
+}
+
+fn main() {
+    let mut current_inventory = Inventory {
+        shirts: vec![
+            ShirtColor::Red,
+            ShirtColor::Red,
+            ShirtColor::Green,
+            ShirtColor::Green,
+            ShirtColor::Green,
+            ShirtColor::Blue,
+            ShirtColor::Blue,
+            ShirtColor::Blue,
+            ShirtColor::Blue,
+        ],
+    };
+
+    let user_red = User {
+        shirt_preference: Some(ShirtColor::Red),
+    };
+    let user_green = User {
+        shirt_preference: Some(ShirtColor::Green),
+    };
+    let user_none = User {
+        shirt_preference: None,
+    };
+
+    println!("DEBUG: inventory: {:?}", current_inventory);
+    println!("--------------------");
+
+    println!(
+        "DEBUG: giveaway {:?} to {:?}",
+        Inventory::giveaway(&mut current_inventory, &user_red),
+        user_red
+    );
+
+    println!("DEBUG: current inventory: {:?}", current_inventory);
+
+    println!("--------------------");
+
+    println!(
+        "DEBUG: giveaway {:?} to {:?}",
+        Inventory::giveaway(&mut current_inventory, &user_green),
+        user_green
+    );
+
+    println!("DEBUG: current inventory: {:?}", current_inventory);
+    println!("--------------------");
+
+    println!(
+        "DEBUG: giveaway {:?} to {:?}",
+        Inventory::giveaway(&mut current_inventory, &user_none),
+        user_none
+    );
+
+    println!("DEBUG: current inventory: {:?}", current_inventory);
+    println!("--------------------");
+}