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# Numbrix Path Puzzle

[GitHub](https://github.com/HectorTablero/QED-Scripts/blob/main/Magazine%202/Puzzles/numbrix.js) | [Live Demo](https://qed.mat.uam.es/revista/articulo/acertijos-2)

**Date:** June 2024
**Technologies:** JavaScript, Tailwind CSS

---

## Overview

Numbrix is a logic puzzle where players fill a grid with consecutive numbers such that each number is orthogonally adjacent to the next. The puzzle provides some pre-filled numbers as clues, and players must connect them in sequence.

## Implementation Details

### Puzzle Structure

The element receives a 2D array where `0` represents empty cells and non-zero values are fixed clues. The goal is to fill all cells with numbers from 1 to (width × height) such that consecutive numbers are adjacent horizontally or vertically.

```javascript
// Example element configuration
::: js Numbrix
    [
        [0,15,10,9,8,0],
        [17,0,0,0,0,6],
        [18,0,12,3,0,1],
        [19,0,25,26,0,30],
        [20,0,0,0,0,31],
        [0,22,35,34,33,0]
    ]
    numbrix1
    autoPlay, allowFullscreen, saveStates
:::
```

### Validation Logic

The element validates three conditions:

1. **Completeness**: All cells must contain valid numbers (1 to total cells)
2. **Uniqueness**: Each number appears exactly once
3. **Connectivity**: Consecutive numbers must be orthogonally adjacent

The validation uses a positions map to track number locations, then iterates through consecutive pairs to check adjacency using Manhattan distance.

### UI Features

**Fixed Cells**: Pre-filled numbers are displayed with bold font and a gray background, and their inputs are disabled to prevent modification.

**Dynamic Borders**: The grid uses variable border widths (2px on edges, 1px internally) to create a clean visual boundary while maintaining cell separation.

**Input Validation**: Accepts only numeric input with a maximum length equal to the total number of cells (e.g., 2 digits for grids up to 99 cells).

### Technical Considerations

The element maintains two separate grids: `given` (immutable initial state) and `grid` (current user input). This separation allows reset functionality and clear distinction between clues and user answers.

State persistence saves only the `grid` array, as the `given` array is reconstructed from parameters on each initialization.