Robot Path Lab – Multi-language Intro Programming Demo Pseudocode → Python / Java / C++ · Grid visualization · Out-of-bounds checks

Students write a tiny movement pseudocode on the left (using commands like RIGHT 3 and UP 2). On the right, a robot 🤖 walks on a square grid. Below the editor, the same pseudocode is translated into Python, Java, or C/C++ so that students can compare different languages.
🧾 Pseudocode editor (students type commands here)
Supported commands (one per line): RIGHT n, LEFT n, UP n, DOWN n, MARK. Lines starting with # are comments. The robot starts at the bottom-left; the target is at the top-right.
Example program:
RIGHT 3
UP 2
LEFT 1
DOWN 1
View translation as:
The box below shows how this pseudocode might look in the selected language.
Grid size: × 8
🤖 Robot grid visualization
The grid is an N×N board. The robot starts in the bottom-left cell, and the target is in the top-right cell. If a command tries to move outside the board, the system shows an “out-of-bounds” error and stops.
Legend: 🤖 robot | 🟥 target cell | 🟦 visited path
Coordinates: x increases to the right, y increases downward. The robot starts at (0, N−1) and the target is at (N−1, 0).
Robot console (position updates and errors): 


        

          Execution view (current pseudocode line is highlighted while the robot moves):
        

        


        

          Learning objectives & CS1 concepts:
          
    
            
  • Understand sequential execution: commands run from top to bottom.
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  • Connect pseudocode to state changes on a grid (the robot’s (x, y) position).
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  • Compare three languages (Python, Java, C/C++) implementing the same logic.
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  • Recognize the role of parameters and boundaries (out-of-bounds errors).
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  • Practice debugging and tracing by predicting paths and checking the visual result.
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