A-Puzzle-A-Day Hint Generator

A web-based hint system for the DragonFjord "A-Puzzle-A-Day" puzzle. Instead of showing full solutions, it lets you progressively reveal hints by placing one piece at a time.

Live Site: https://www.puzzleadayhint.com (or https://icy-moss-05a1e991e.6.azurestaticapps.net)

Features

• Select any date (month + day) to find all valid solutions
• Click a piece to see where it can be placed (highlighted in green)
• Place pieces one at a time - solutions filter as you go
• Shows count of remaining solutions after each placement
• Mobile-friendly responsive design
• Fast solver using bitmask operations (~50-200ms per date)

The Puzzle

The A-Puzzle-A-Day puzzle has:

• Board: 7x7 grid with 6 blocked cells (43 usable cells)
• 8 Pieces: 1 rectangle (6 cells) + 7 pentominoes (5 cells each) = 41 cells
• Goal: Cover all cells except the current month and day

Project Structure

puzzle-hint-generator/
├── index.html                 # Single-file app (HTML + CSS + JS)
├── staticwebapp.config.json   # Azure Static Web Apps config
├── README.md                  # This file
└── .github/
    └── workflows/
        └── azure-static-web-apps-icy-moss-05a1e991e.yml  # Auto-deploy workflow

Local Development

Just open index.html in a browser - no build step or server needed.

# Or use a local server
npx serve .

Deployment

The site auto-deploys to Azure Static Web Apps on every push to master.

Manual Deployment

# Get deployment token from Azure
az staticwebapp secrets list --name puzzleadayhint --resource-group Puzzleadayhint_group --query "properties.apiKey" -o tsv

# Deploy
swa deploy . --deployment-token "<token>" --env production

Azure Resources

• Resource Group: Puzzleadayhint_group
• Static Web App: puzzleadayhint
• Region: West US 2
• SKU: Free
• GitHub Repo: https://github.com/TheLineExp/puzzleadayhint

Custom Domain Setup

Current Domains

• www.puzzleadayhint.com - CNAME to icy-moss-05a1e991e.6.azurestaticapps.net
• puzzleadayhint.com - Requires TXT validation for apex domain

DNS Records (at your registrar)

Type	Name	Value
CNAME	www	icy-moss-05a1e991e.6.azurestaticapps.net
ALIAS	@	icy-moss-05a1e991e.6.azurestaticapps.net

For apex domain validation:

az staticwebapp hostname show -n puzzleadayhint -g Puzzleadayhint_group --hostname puzzleadayhint.com --query "validationToken"

Add returned value as TXT record at @.

Code Overview

Piece Definitions

8 pieces defined as coordinate arrays, with rotations/reflections auto-generated:

const PIECE_BASES = [
    { name: 'Rectangle', base: [[0,0],[0,1],[0,2],[1,0],[1,1],[1,2]], reflect: false },
    { name: 'U-shape',   base: [[0,0],[0,1],[1,0],[2,0],[2,1]], reflect: false },
    { name: 'Corner',    base: [[0,0],[0,1],[0,2],[1,0],[2,0]], reflect: false },
    { name: 'S-shape',   base: [[0,0],[1,0],[1,1],[2,1],[3,1]], reflect: true },
    { name: 'L-shape',   base: [[0,0],[1,0],[2,0],[3,0],[3,1]], reflect: true },
    { name: 'Z-shape',   base: [[0,0],[0,1],[1,1],[2,1],[2,2]], reflect: true },
    { name: 'T-shape',   base: [[0,0],[0,1],[0,2],[0,3],[1,1]], reflect: true },
    { name: 'P-shape',   base: [[0,0],[0,1],[1,0],[1,1],[2,0]], reflect: true }
];

Solver Algorithm

1. Bitmask representation: Board state as 64-bit BigInt for O(1) collision detection
2. Pre-computed placements: All valid positions for each piece orientation calculated once
3. Pruning: Flood-fill detects isolated regions too small for remaining pieces
4. Backtracking: Recursive search through all piece placements

Key Functions

Function	Description
findAllSolutions(month, day)	Returns array of all valid solutions
generateOrientations(shape)	Creates all rotations/reflections of a piece
hasIsolatedRegion(board)	Pruning check for unsolvable states
showValidPlacements(pieceIdx)	Highlights valid cells for selected piece
placePiece(pieceIdx, placement)	Places piece and filters remaining solutions

Making Changes

Update Piece Shapes

Edit PIECE_BASES array in index.html (around line 242)

Change Colors

Edit CSS variables and .color-N classes (lines 8-169)

Modify Board Layout

Edit BOARD_LABELS and BLOCKED arrays (lines 185-196)

Adjust Mobile Breakpoints

Edit @media queries at end of <style> block (lines 171-196)

Troubleshooting

Solver finds no solutions

• Check piece definitions total 41 cells
• Verify blocked cells leave 43 usable cells
• Ensure target date cells are valid

Deployment fails

• Check GitHub Actions logs: https://github.com/TheLineExp/puzzleadayhint/actions
• Verify app_location: "/" in workflow file
• Ensure deployment token is valid

Custom domain not working

• DNS propagation can take up to 48 hours
• Verify CNAME points to correct Azure hostname
• Check Azure Portal for validation status

Resources

• DragonFjord A-Puzzle-A-Day
• Azure Static Web Apps Docs
• Reference Solver (Rust)