Solution

app/main.py

@@ -1,34 +1,110 @@
+from typing import List, Tuple, Dict
+
+
 class Deck:
-    def __init__(self, row, column, is_alive=True):
-        pass
+    def __init__(self, row: int, column: int) -> None:
+        self.row: int = row
+        self.column: int = column
+        self.is_alive: bool = True
+
+    def hit(self) -> None:
+        self.is_alive = False
 
 
 class Ship:
-    def __init__(self, start, end, is_drowned=False):
-        # Create decks and save them to a list `self.decks`
-        pass
+    def __init__(self, start: Tuple[int, int], end: Tuple[int, int]) -> None:
+        self.start: Tuple[int, int] = start
+        self.end: Tuple[int, int] = end
+        self.decks: List[Deck] = self.create_decks(start, end)
+        self.is_drowned: bool = False
+
+    def create_decks(self,
+                     start: Tuple[int, int],
+                     end: Tuple[int, int]) -> List[Deck]:
+        decks: List[Deck] = []
+        if start[0] == end[0]:
+            for col in range(start[1], end[1] + 1):
+                decks.append(Deck(start[0], col))
+        else:
+            for row in range(start[0], end[0] + 1):
+                decks.append(Deck(row, start[1]))
+        return decks
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        pass
+    def fire(self, row: int, column: int) -> None:
+        for deck in self.decks:
+            if deck.row == row and deck.column == column:
+                deck.hit()
+                break
+        self.update_is_drowned()
 
-    def fire(self, row, column):
-        # Change the `is_alive` status of the deck
-        # And update the `is_drowned` value if it's needed
-        pass
+    def update_is_drowned(self) -> None:
+        self.is_drowned = all(not deck.is_alive for deck in self.decks)
 
 
 class Battleship:
-    def __init__(self, ships):
-        # Create a dict `self.field`.
-        # Its keys are tuples - the coordinates of the non-empty cells,
-        # A value for each cell is a reference to the ship
-        # which is located in it
-        pass
-
-    def fire(self, location: tuple):
-        # This function should check whether the location
-        # is a key in the `self.field`
-        # If it is, then it should check if this cell is the last alive
-        # in the ship or not.
-        pass
+    def __init__(self,
+                 ships: List[Tuple[Tuple[int, int], Tuple[int, int]]]) -> None:
+        self.field: Dict[Tuple[int, int], Ship] = {}
+        self.ships: List[Ship] = []
+        for start, end in ships:
+            ship = Ship(start, end)
+            self.ships.append(ship)
+            for deck in ship.decks:
+                self.field[(deck.row, deck.column)] = ship
+
+    def fire(self, location: Tuple[int, int]) -> str:
+        if location not in self.field:
+            return "Miss!"
+        ship = self.field[location]
+        ship.fire(location[0], location[1])
+        if ship.is_drowned:
+            return "Sunk!"
+        return "Hit!"
+
+    def print_field(self) -> None:
+        field_representation: List[List[str]] = [["~"] * 10 for _ in range(10)]
+        for ship in self.ships:
+            for deck in ship.decks:
+                if not deck.is_alive:
+                    symbol = "x" if ship.is_drowned else "*"
+                else:
+                    symbol = "□"
+                field_representation[deck.row][deck.column] = symbol
+        for row in field_representation:
+            print(" ".join(row))
+
+    def _validate_field(self) -> None:
+        if len(self.ships) != 10:
+            raise ValueError("The total number of ships should be 10")
+        counts: Dict[int, int] = {1: 0, 2: 0, 3: 0, 4: 0}
+        for ship in self.ships:
+            length: int = len(ship.decks)
+            if length in counts:
+                counts[length] += 1
+        if (
+                counts
+                [1] != 4 or counts[2] != 3 or counts[3] != 2 or counts[4] != 1
+        ):
+            raise ValueError("Invalid number of ships of each type")
+        self._check_no_neighbors()
+
+    def _check_no_neighbors(self) -> None:
+        directions: List[Tuple[int, int]] = [
+            (-1, -1), (-1, 0), (-1, 1),
+            (0, -1), (0, 1),
+            (1, -1), (1, 0), (1, 1)
+        ]
+        for ship in self.ships:
+            for deck in ship.decks:
+                for direction in directions:
+                    neighbor: Tuple[int, int] = (
+                        deck.row + direction[0],
+                        deck.column + direction[1]
+                    )
+                    if (
+                            neighbor
+                            in self.field and self.field[neighbor] != ship
+                    ):
+                        raise ValueError(
+                            "Ships are located in neighboring cells"
+                        )