Solution

app/main.py

@@ -1,34 +1,110 @@
+class ValidationError(Exception):
+    pass
+
+
 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
+
+    def __repr__(self) -> str:
+        return f"({self.row}; {self.column})"
 
 
 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: list,
+            end: list,
+            is_drowned: bool = False
+    ) -> None:
+        if start[0] == end[0]:
+            self.decks = [
+                Deck(start[0], i)
+                for i in range(start[1], end[1] + 1)
+            ]
+        if start[1] == end[1]:
+            self.decks = [
+                Deck(i, start[1])
+                for i in range(start[0], end[0] + 1)
+            ]
+        self.is_drowned = is_drowned
+
+    def __str__(self) -> str:
+        return f"{self.decks}"
+
+    def __repr__(self) -> str:
+        return f"{self.decks}"
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        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 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) -> str:
+        deck = self.get_deck(row, column)
+        deck.is_alive = False
+        self.is_drowned = all([
+            not deck.is_alive
+            for deck in self.decks
+        ])
+        return "Sunk!" if self.is_drowned else "Hit!"
 
 
 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) -> None:
+        self.field = {
+            ship: Ship(*ship)
+            for ship in ships
+        }
+        self._validate_field()
+
+    def fire(self, loc: tuple) -> str:
+        for coords, ship in self.field.items():
+            ship_decks = ship.get_deck(*loc)
+            if ship_decks is not None:
+                return ship.fire(*loc)
+        return "Miss!"
+
+    def _validate_field(self) -> None:
+        if len(self.field) != 10:
+            raise ValidationError("Total amount of the ships should be 10")
+        ships = [0] * 4
+        for coords, ship in self.field.items():
+            if coords[0] == coords[1]:
+                ships[0] += 1
+                continue
+            diff = [coords[1][0] - coords[0][0], coords[1][1] - coords[0][1]]
+            if diff[0] == 0:
+                ships[diff[1]] += 1
+            elif diff[1] == 0:
+                ships[diff[0]] += 1
+
+        if ships[0] != 4 or ships[1] != 3 or ships[2] != 2 or ships[3] != 1:
+            raise ValidationError("there should be 4 single-deck ships\n"
+                                  "there should be 3 double-deck ships\n"
+                                  "there should be 2 three-deck ships\n"
+                                  "there should be 1 four-deck ship"
+                                  )
+
+    def print_field(self) -> None:
+        for i in range(0, 10):
+            for j in range(0, 10):
+                coord = (i, j)
+                for coords, ship in self.field.items():
+                    deck = ship.get_deck(*coord)
+                    if deck is not None:
+                        if ship.is_drowned:
+                            print("x ", end="")
+                            break
+                        if not deck.is_alive:
+                            print("* ", end="")
+                            break
+                        print(u"\u25A1 ", end="")
+                        break
+                else:
+                    print("~ ", end="")
+            print()
+        print()
+        return