Teaching Tip 1: Rook Validator

With reference to Part 2 ask your students to write a script that accepts two coordinates (start and finish) and returns True if the move is geometrically valid for a Rook, and False otherwise.

Applied Concepts

• Integer variables for coordinates.

• Comparison operators (==, !=).

• Conditional blocks.

Show and discuss the solution:

SOLUTION
def validate_rook_move(start_r, start_c, end_r, end_c):
    """
    Checks if the move is geometrically valid for a Rook.
    Does not check for obstacles in the path.
    """  
# 1. Basic check: Did the rook actually move?
# If row AND column are the same, the piece stayed still.
if start_r == end_r and start_c == end_c:
    return False # Illegal null move
    
# 2. Geometric check
    if start_r == end_r:
        # Row is the same, so it moved along the column (Horizontal)
        return True
    elif start_c == end_c:
        # Column is the same, so it moved along the row (Vertical)
        return True
    else:
        # Neither row nor column is preserved (e.g., diagonal)
        return False

# Testing the code
print(f"Move 1 (Horizontal): {validate_rook_move(0, 0, 0, 5)}") # True
print(f"Move 2 (Diagonal):   {validate_rook_move(0, 0, 5, 5)}") # False

Teaching Tip 2: Checking Piece Color

Challenge students with the following task:

In FEN, uppercase is white and lowercase is black. Write a small script that, given a variable piece = "q", uses an if-else statement to print "Black" if the piece is "q" or "White" if the piece is "Q".

SOLUTION
piece = "q"
if piece == "q":
   print("Black")
else:
   print("White")

Teaching Tip 3: Null Move Validator

Challenge students with the following task:

A move is "null" if the starting position (r1, c1) is identical to the destination (r2, c2). Write an if block that checks this condition and prints "Invalid move: the piece stayed still" if the coordinates match.

SOLUTION 
r1, c1 = 4, 4
r2, c2 = 4, 4
if r1 == r2 and c1 == c2:
    print("Invalid move: the piece stayed still")

Teaching Tip 4: The Rook at the Edges

Challenge students with the following task:

Write a program that takes a variable column. If the column is 0 print "Left edge", if it is 7 print "Right edge", otherwise print "Central column".

SOLUTION 
column = 7
if column == 0:
    print("Left edge")
elif column == 7:
    print("Right edge")
else:
    print("Central column")

Teaching Tip 5: Calculating Distance (Delta)

Challenge students with the following task:

Given r1 = 2 and r2 = 5, write the Python code that calculates the absolute difference between the two rows, saves it in the variable delta_r, and prints it.

SOLUTION 
r1 = 2
r2 = 5
delta_r = abs(r1 - r2)
print(delta_r) # Output: 3

Teaching Tip 6: Occupied Square Checker

Challenge students with the following task:

Given a variable square = ".", write an if statement that checks if the square is occupied (i.e., if it is not equal to a dot) and prints "Square occupied".

SOLUTION 
square = "R" # Example: there is a Rook
if square != ".":
    print("Square occupied")