'Solution'

app/main.py

@@ -1,34 +1,94 @@
 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]:
+        decks = []
+        if self.start[0] == self.end[0]:  # Horizontal ship
+            for col in range(self.start[1], self.end[1] + 1):
+                decks.append(Deck(self.start[0], col))
+        else:  # Vertical ship
+            for row in range(self.start[0], self.end[0] + 1):
+                decks.append(Deck(row, self.start[1]))
+        return decks
 
-    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
+        return None
+
+    def fire(self, row: int, column: int) -> bool:
+        deck = self.get_deck(row, column)
+        if deck and deck.is_alive:
+            deck.is_alive = False
+            self.is_drowned = all(not d.is_alive for d in self.decks)
+            return True
+        return False
 
 
 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 = {}
+        self.ships = []
+        for ship_coords in ships:
+            ship = Ship(*ship_coords)
+            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]
+        row, col = location
+        hit = ship.fire(row, col)
+        if not hit:
+            return "Miss!"
+        if ship.is_drowned:
+            return "Sunk!"
+        return "Hit!"
+
+    def print_field(self) -> None:
+        field_visual = [["~" for _ in range(10)] for _ in range(10)]
+        for (row, col), ship in self.field.items():
+            deck = ship.get_deck(row, col)
+            if deck.is_alive:
+                field_visual[row][col] = "□"
+            elif ship.is_drowned:
+                field_visual[row][col] = "x"
+            else:
+                field_visual[row][col] = "*"
+        for row in field_visual:
+            print(" ".join(row))
+
+    def _validate_field(self) -> bool:
+        ship_counts = {1: 0, 2: 0, 3: 0, 4: 0}
+        for ship in self.ships:
+            length = len(ship.decks)
+            if length in ship_counts:
+                ship_counts[length] += 1
+        return (
+            ship_counts[1] == 4
+            and ship_counts[2] == 3
+            and ship_counts[3] == 2
+            and ship_counts[4] == 1
+        )