Karel Answer [work]: 6.4.5 Checkerboard

turnAround(); while (frontIsClear()) move();

/* 6.4.5 Checkerboard Karel * This program makes Karel create a checkerboard * pattern of beepers across any size world. */ function start() // Fill the first row putBeeper(); fillRow(); // Move up and handle subsequent rows while (leftIsClear()) repositionForNextRow(); fillRow(); // Karel fills a single row based on the previous space function fillRow() while (frontIsClear()) move(); if (frontIsClear()) move(); putBeeper(); // Logic to move Karel up one row and face the right direction function repositionForNextRow() if (facingEast()) if (leftIsClear()) turnLeft(); checkAndMoveUp(); turnLeft(); else if (rightIsClear()) turnRight(); checkAndMoveUp(); turnRight(); // Helper to ensure we don't place two beepers next to each other vertically function checkAndMoveUp() if (beepersPresent()) move(); // If row started with beeper, the one above starts empty else move(); putBeeper(); // Basic movement functions function turnRight() turnLeft(); turnLeft(); turnLeft(); Use code with caution. Key Concepts to Remember 1. The "Skip-One" Logic

turnRight(); if (frontIsClear()) move(); turnRight();

A more robust logic often requires handling the move sequence differently or initializing the first square. Let's look at the that is widely accepted as the correct answer because it handles the odd/even column count automatically 6.4.5 checkerboard karel answer

fillRow() putBeeper(); (frontIsClear()) move();

These skills translate directly to real programming: traversing 2D arrays, handling variable-length data, and maintaining invariants in loops.

loop to move Karel across the world. Inside, use a helper function to decide when to place a beeper. turnAround(); while (frontIsClear()) move(); /* 6

Check your fillRow function. Ensure there is a frontIsClear() check before every move() .

(frontIsClear()) move(); putBeeper();

if (frontIsClear()) move();

function fillRow() putBeeper(); while(frontIsClear()) move(); if(frontIsClear()) move(); putBeeper();

There are several ways to solve the alternating pattern, but the most robust method involves checking Karel's direction or the state of the corner she is standing on.

: Each row must alternate its starting beeper position. If the previous row ended with a beeper, the next row must start with an empty space to maintain the checkerboard pattern. Course Hero 2. Implementation Steps 1. Define the Start Function Inside, use a helper function to decide when