board.py

import random
#### Functions related to the game board
## All n definded by board size are - 1 for padding but not for placing ships

# Function to create a blank board 
def create_board(n):
    board = [] # Initialize an empty list
    for r in range(n+1): # for loop from 0 to rows - 1
        row = [] # Initialize an empty list for each row
        for c in range(n+1): # for loop from 0 to cols - 1
            row.append('*') # Append a . to the row list
        board.append(row) # Append the row list to the board list
    return board # note: this is not a rxc matrix but a list of lists

# Checker for placing a ship
def can_place_ship(board, row, col, orientation, size):
    n = len(board) - 1
    
    if orientation == 'H':
        # must fit to the right
        if col + size > n:
            return False
        # check for overlap/neighbors
        for i in range(size + 2):
            if board[row][col - 1 + i] != '*':
                return False
            if row == 0: # top edge
                if board[row + 1][col - 1 + i] != '*':
                    return False
            elif row == n -1: # bottom edge
                if board[row - 1][col - 1 + i] != '*':
                    return False
            else: # middle rows
                if board[row - 1][col - 1 + i] != '*':
                    return False
                if board[row + 1][col - 1 + i] != '*':
                    return False
            
        return True
    elif orientation == 'V':
        # must fit downward
        if row + size > n:
            return False
        # check for overlap/neighbors
        for i in range(size + 2):
            if board[row - 1 + i][col] != '*':
                return False
            if col == 0: # left edge
                if board[row - 1 + i][col + 1] != '*':
                    return False
            elif col == n -1: # right edge
                if board[row - 1 + i][col - 1] != '*':
                    return False
            else: # middle cols
                if board[row - 1 + i][col - 1] != '*':
                    return False
                if board[row - 1 + i][col + 1] != '*':
                    return False
        return True
    
    else:
        return False # invalid orientation
    
# place a ship on the board
# Orientation is H or V
def place_ship(board, row, col, orientation, size):
    if not can_place_ship(board, row, col, orientation, size):
        return False # Cannot place ship here
    
    if orientation == 'H':
        for i in range(size):
            board[row][col + i] = 'S'
    elif orientation == 'V':
        for i in range(size):
            board[row + i][col] = 'S'
    return True

# Fleet definitions by board size
def fleet_for_n(n):
    if n == 8:
        return [4, 3, 3, 3, 2, 2, 2]
    elif n == 9:
        return [4,4,4,3,3,3,3,3] 
    elif n == 10:
        return [4,3,3,2,2,2,1,1,1,1]
    else:
        raise ValueError("Unsupported board size for fleet definition")

# randomly place one ship
def randomly_place_ship(board, size, nmax=1000):
    n = len(board) - 1
    placed = False
    tries = 1
    while not placed:
        orientation = random.choice(['H', 'V'])
        if orientation == 'H':
            row = random.randint(0, n - 1)
            col = random.randint(0, n - size)
        else: # V
            row = random.randint(0, n - size)
            col = random.randint(0, n - 1)
        
        if place_ship(board, row, col, orientation, size):
            return True
        tries += 1
        if tries > nmax:
            print("Failed to place ship of size", size)
            break
    return False

# Place the whole fleet
def place_fleet(n, board):
    fleet = fleet_for_n(n)
    for size in fleet:
        if not randomly_place_ship(board, size):
            print("Failed to place the entire fleet.")
            raise RuntimeError("Could not place fleet")
    return board

# Fxn to print board
def print_board(board):
    n = len(board) - 1 # Get number of rows and cols
    # print column numbers
    print("  ", end="") # Print initial spaces
    for c in range(n): # for loop from 0 to cols - 1
        print(c, end=" ") # Print column number with space
    print() # Print a new line after column numbers

    #Print rows
    for r in range(n): # for loop from 0 to rows - 1
        row_label = chr(ord('A') + r) # Convert row number to letter
        print(f"{row_label} ", end="") # Print row label with space
        for c in range(n): # for loop from 0 to cols - 1
            print(board[r][c], end=" ") # Print the element at row r and col c with a space
        print() # Print a new line after each row