Solution

app/main.py

@@ -1,34 +1,102 @@
 class Deck:
-    def __init__(self, row, column, is_alive=True):
-        pass
+    def __init__(self, row: int, column: int, is_alive: bool = True) -> None:
+        self.row = row
+        self.column = column
+        self.is_alive = is_alive
 
 
 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],
+            is_drowned: bool = False
+    ) -> None:
+        self.is_drowned = is_drowned
+        self.decks = []
+        (row1, column1), (row2, column2) = start, end
+        if row1 == row2:
+            for column in range(
+                    min(column1, column2), max(column1, column2) + 1
+            ):
+                self.decks.append(Deck(row1, column))
+        elif column1 == column2:
+            for row in range(min(row1, row2), max(row1, row2) + 1):
+                self.decks.append(Deck(row, column1))
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        pass
+    def get_deck(self, row: int, column: int) -> Deck:
+        for deck in self.decks:
+            if deck.row == row and deck.column == column:
+                return deck
 
-    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 fire(self, row: int, column: int) -> None:
+        self.get_deck(row, column).is_alive = False
+        if not any(deck.is_alive for deck in self.decks):
+            self.is_drowned = True
 
 
 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]]]) -> None:
+        self.field = {}
+        for ship in ships:
+            current_ship = Ship(*ship)
+            for deck in current_ship.decks:
+                self.field[(deck.row, deck.column)] = current_ship
+
+        self._validate_field()
+
+    def fire(self, location: tuple[int, int]) -> str:
+        if location in self.field:
+            self.field[location].fire(*location)
+            if self.field[location].is_drowned:
+                return "Sunk!"
+            return "Hit!"
+        return "Miss!"
+
+    def print_field(self) -> None:
+        field = [["^" for _ in range(10)] for _ in range(10)]
+
+        for deck_coordinates in self.field:
+            ship = self.field[deck_coordinates]
+            deck = ship.get_deck(*deck_coordinates)
+            if deck.is_alive:
+                field[deck.row][deck.column] = u"\u25A1"
+            elif ship.is_drowned:
+                field[deck.row][deck.column] = "x"
+            else:
+                field[deck.row][deck.column] = "*"
+
+        for row in range(10):
+            print(field[row])
+
+    def _validate_field(self) -> None:
+        ship_sizes = {1: 0, 2: 0, 3: 0, 4: 0}
+        for ship in set(self.field.values()):
+            ship_size = len(ship.decks)
+            if ship_size in ship_sizes:
+                ship_sizes[ship_size] += 1
+
+        for ship_size, count in ship_sizes.items():
+            if 5 - ship_size != count:
+                raise ValueError("Invalid number of ships.")
+
+        directions = [
+            (-1, -1),
+            (-1, 0),
+            (-1, 1),
+            (0, -1),
+            (0, 1),
+            (1, -1),
+            (1, 0),
+            (1, 1)
+        ]
+        for (row, column), ship in self.field.items():
+            for row_direction, column_direction in directions:
+                neighbor_cell = (
+                    row + row_direction, column + column_direction
+                )
+                if (
+                    neighbor_cell in self.field
+                    and self.field[neighbor_cell] != ship
+                ):
+                    raise ValueError("Ships are too close.")