Solution

app/main.py

@@ -1,34 +1,150 @@
 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.start = start
+        self.end = end
+        self.is_drowned = is_drowned
+        self.decks = self.create_decks()
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        pass
+    def create_decks(self) -> list[Deck]:
+        start_row, start_column = self.start
+        end_row, end_column = self.end
+        if start_row == end_row:
+            return [
+                Deck(start_row, current_column)
+                for current_column in range(start_column, end_column + 1)
+            ]
+        return [
+            Deck(current_row, start_column)
+            for current_row in range(start_row, end_row + 1)
+        ]
 
-    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 get_deck(self, row: int, column: int) -> Deck | None:
+        for deck in self.decks:
+            if deck.row == row and deck.column == column:
+                return deck
+
+    def check_if_drowned(self) -> None:
+        for deck in self.decks:
+            if deck.is_alive:
+                return
+        self.is_drowned = True
+
+    def fire(self, row: int, column: int) -> None:
+        deck = self.get_deck(row, column)
+        if deck:
+            deck.is_alive = False
+            self.check_if_drowned()
 
 
 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]]) -> None:
+        self.field = {}
+
+        for ship in ships:
+            start, end = ship
+            start_row, start_column = start
+            end_row, end_column = end
+            ship_instance = Ship(start, end)
+            if start_row == end_row:
+                for current_column in range(start_column, end_column + 1):
+                    self.field[(start_row, current_column)] = ship_instance
+            else:
+                for current_row in range(start_row, end_row + 1):
+                    self.field[(current_row, start_column)] = ship_instance
+
+        if not self._validate_field():
+            raise ValueError("Invalid field configuration")
+
+    def fire(self, location: tuple[int, int]) -> str:
+        if location not in self.field:
+            return "Miss!"
+
+        ship = self.field[location]
+        ship.fire(*location)
+        return "Sunk!" if ship.is_drowned else "Hit!"
+
+    def print_field(self) -> None:
+        for row in range(10):
+            for column in range(10):
+                ship = self.field.get((row, column))
+                if not ship:
+                    print("~", end="")
+                    continue
+
+                deck = ship.get_deck(row, column)
+                if deck.is_alive:
+                    print(u"\u25A1", end="")
+                elif ship.is_drowned:
+                    print("x", end="")
+                else:
+                    print("*", end="")
+
+            print()
+
+    def _validate_field(self) -> bool:
+        ships = list(set(self.field.values()))
+        if len(ships) != 10:
+            print(f"The total number of the ships should be 10, "
+                  f"but got {len(ships)} instead")
+            return False
+
+        single_deck, double_deck, three_deck, four_deck = [0, 0, 0, 0]
+        for ship in ships:
+            decks = len(ship.decks)
+            if decks == 1:
+                single_deck += 1
+            elif decks == 2:
+                double_deck += 1
+            elif decks == 3:
+                three_deck += 1
+            elif decks == 4:
+                four_deck += 1
+        wrong = 0
+        if single_deck != 4:
+            print(f"Field should have 4 single-deck ships, "
+                  f"but got {single_deck} instead")
+            wrong += 1
+        if double_deck != 3:
+            print(f"Field should have 3 double-deck ships, "
+                  f"but got {double_deck} instead")
+            wrong += 1
+        if three_deck != 2:
+            print(f"Field should have 2 three-deck ships, "
+                  f"but got {three_deck} instead")
+            wrong += 1
+        if four_deck != 1:
+            print(f"Field should have 1 four-deck ship, "
+                  f"but got {four_deck} instead")
+            wrong += 1
+        if wrong > 0:
+            return False
+
+        for deck_location, ship in self.field.items():
+            current_row, current_column = deck_location
+            for row in range(current_row - 1, current_row + 2):
+                for column in range(current_column - 1, current_column + 2):
+                    neighbor_location = (row, column)
+                    if (
+                            0 <= row <= 9
+                            and 0 <= column <= 9
+                            and neighbor_location != deck_location
+                    ):
+                        neighbor = self.field.get(neighbor_location)
+                        if neighbor and neighbor is not ship:
+                            print("Ships shouldn't be located "
+                                  "in the neighboring cells "
+                                  "(even if cells are neighbors by diagonal)")
+                            return False
+        return True