0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 Use code with caution.
Karel must finish the grid without crashing into walls. Common Bugs in Student Code
You need an outer loop for rows and an inner loop for columns.
Let's break down the fixed code:
For Karel-based versions, the robot must move across the grid while painting alternating colors: 916 checkerboard v1 codehs fixed
: An outer loop controls the rows (vertical movement), while an inner loop handles the columns (horizontal movement).
grid of squares where the colors alternate between black and red (or other assigned colors), resembling a standard checkerboard. Key Technical Requirements:
function transitionToEast() turnRight(); if (frontIsClear()) move(); turnRight(); Use code with caution. Step 3: Integrating Parity Checks
main()
This function handles the crucial logic of moving up one row and switching directions (East ↔left-right arrow
// Function to create the checkerboard function start() // Set up the graphics window var canvasWidth = BOARD_WIDTH; var canvasHeight = BOARD_HEIGHT; var board = new Canvas(canvasWidth, canvasHeight);
Ensure you loop rows 0–7 and columns 0–7.
The "9.1.6 Checkerboard, v1" assignment is a foundational programming exercise that teaches essential concepts like nested loops, 2D grid manipulation, conditional logic, and coordinate-based positioning. The "fixed" version requires careful attention to the alternating pattern logic, proper position calculations, and thorough testing of edge cases. 0 1 0 1 0 1 0 1
To fix the 9.1.6 Checkerboard V1 exercise in CodeHS (Karel), the primary challenge is ensuring the "ball" pattern alternates correctly regardless of whether the row has an even or odd number of spaces.
If Karel ends a row on a space that , the first space of the next row should not have a ball . You can handle this by adjusting whether your transition function makes an extra move before starting the next drawRow() cycle. Final Checklist for a Perfect Score
Forgetting to move the cursor or break to a new line after the inner loop finishes.
x += SIZE # FIX: Decrement col_count col_count -= 1 Let's break down the fixed code: For Karel-based
. You can do this quickly using a list comprehension: board = [[0] * 8 for _ in range(8)] .