Solution

app/main.py

@@ -1,34 +1,148 @@
+class BattleshipActivationError(Exception):
+    def __init__(
+            self,
+            message: str = "Creating ships doesn't meet the conditions!"
+    ) -> None:
+        super().__init__(message)
+
+
 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,
+            end: tuple,
+            is_drowned: bool = False
+    ) -> None:
+        self.start = start
+        self.end = end
+        self.is_drowned = is_drowned
+        self.forbidden_cells = set()
+        self.decks = self.set_decks_list(self.start, self.end)
+
+    def set_decks_list(
+            self,
+            start_point: tuple,
+            end_point: tuple
+    ) -> list[Deck]:
+        row_s, column_s = start_point
+        row_e, column_e = end_point
+        self.get_forbidden_cells(row_s, column_s, row_e, column_e)
+        if row_s == row_e:
+            return [
+                Deck(row_s, point) for point
+                in range(column_s, column_e + 1)
+            ]
+        else:
+            return [
+                Deck(point, column_s) for point
+                in range(row_s, row_e + 1)
+            ]
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        pass
+    def get_forbidden_cells(
+            self,
+            row_start: int,
+            column_start: int,
+            row_end: int,
+            column_end: int
+    ) -> None:
+        for row in range(max(0, row_start - 1), min((row_end + 2), 10)):
+            for column in range(
+                    max(0, column_start - 1),
+                    min((column_end + 2), 10)
+            ):
+                self.forbidden_cells.add((row, column))
 
-    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:
+        for el in self.decks:
+            if el.row == row and el.column == column:
+                return el
+
+    def fire(self, row: int, column: int) -> None:
+        self.get_deck(row, column).is_alive = False
+        if all(not 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]) -> None:
+        self.ships = [Ship(*ship) for ship in ships]
+        self.field = self.get_field()
+        self._validate_field(self.ships)
+
+    def get_field(self) -> dict:
+        field = {}
+        for ship in self.ships:
+            for deck in ship.decks:
+                field[(deck.row, deck.column)] = ship
+        return field
+
+    @staticmethod
+    def _validate_field(ships: list[Ship]) -> None:
+        if len(ships) != 10:
+            raise BattleshipActivationError(
+                "The total number of the ships should be 10!"
+            )
+
+        deck_counter = {
+            1: [0, 4, "single-deck"],
+            2: [0, 3, "double-deck"],
+            3: [0, 2, "three-deck"],
+            4: [0, 1, "four-deck"]
+        }
+        for ship in ships:
+            deck_counter[len(ship.decks)][0] += 1
+        for key, value in deck_counter.items():
+            if value[0] != value[1]:
+                raise BattleshipActivationError(
+                    f"There should be {value[1]} {value[2]} "
+                    f"ships, you have {value[0]}!"
+                )
+
+        forbidden_area = set()
+        for ship in ships:
+            for el in ((deck.row, deck.column) for deck in ship.decks):
+                if el in forbidden_area:
+                    raise BattleshipActivationError(
+                        f"It is impossible to place the ship here {el}!"
+                    )
+            forbidden_area.update(ship.forbidden_cells)
+
+    def fire(self, location: tuple) -> str:
+        if location not in self.field.keys():
+            return "Miss!"
+        else:
+            ship = self.field[location]
+            ship.fire(*location)
+            if ship.is_drowned:
+                return "Sunk!"
+            else:
+                return "Hit!"
+
+    def print_field(self) -> None:
+        base_field = [["~" for _ in range(10)] for _ in range(10)]
+
+        for location, ship in self.field.items():
+            row, column = location
+            if ship.is_drowned:
+                base_field[row][column] = "X"
+            elif ship.get_deck(row, column).is_alive:
+                base_field[row][column] = "\u25A1"
+            else:
+                base_field[row][column] = "\u26A1"
+
+        for line in base_field:
+            print(line)
+        print("___________________________________________________")
+        print("'\u25A1' - alive, '\u26A1' - hit, 'X' - drowned\n")