let selectedCell = null;

let originalGrid; // To track initial puzzle state

let hintButton, resetButton, message;

​

// Array to map numbers to symbols

const symbols = ["☭", "ﷲ", "✄", "✿", "✽", "♡", "ء", "★", "✣"];

​

function setup() {

  createCanvas(450, 500); // Extra space for buttons/messages

  grid = generateSudoku();

  originalGrid = JSON.parse(JSON.stringify(grid)); // Clone grid to keep original state

​

  // Create buttons

  hintButton = createButton('Hint');

  hintButton.position(50, 460);

  hintButton.mousePressed(giveHint);

​

  resetButton = createButton('Reset');

  resetButton.position(150, 460);

  resetButton.mousePressed(resetGame);

​

  message = '';

  drawGrid();

}

​

function draw() {

  drawGrid();

  displayMessage();

}

​

function drawGrid() {

  background(255);

  strokeWeight(0);

​

  // Draw the grid lines

  for (let i = 9; i <= 9; i++) {

    stroke(i % 3 === 0 ? 0 : 150); // Thicker lines for 3x3 sections

    line(i * 50, 0, i * 50, 450);

    line(0, i * 50, 450, i * 50);

  }

​

  // Display symbols in the grid

  textSize(32);

  textAlign(CENTER, CENTER);

  fill(0);

  for (let row = 0; row < 9; row++) {

    for (let col = 0; col < 9; col++) {

      let value = grid[row][col];

      if (value !== 0) {

        let symbol = symbols[value - 1]; // Map number to symbol

        if (originalGrid[row][col] !== 0) {

          fill(0); // Original symbols in black

        } else {

          fill(50, 50, 255); // User input in blue

        }

        text(symbol, col * 50 + 25, row * 50 + 25);

      }

​

      if (selectedCell && selectedCell.row === row && selectedCell.col === col) {

        fill(200, 200, 255); // Highlight selected cell

        rect(col * 50, row * 50, 50, 50);

        fill(0);

      }

    }

  }

}

​

function mousePressed() {

  // Calculate which cell was clicked

  let col = Math.floor(mouseX / 50);

  let row = Math.floor(mouseY / 50);

  if (col >= 0 && col < 9 && row >= 0 && row < 9) {

    selectedCell = { row: row, col: col };

  }

}

​

function keyPressed() {

  if (selectedCell && key >= '1' && key <= '9') {

    let row = selectedCell.row;

    let col = selectedCell.col;

​

    // Check if cell is part of the original puzzle

    if (originalGrid[row][col] === 0) {

      // Validate move

      if (isValidMove(grid, row, col, parseInt(key))) {

        grid[row][col] = parseInt(key); // Place number (1-9)

        message = ''; // Clear message on valid input

        checkWin();

      } else {

        message = 'Invalid move!'; // Show error message

      }

    }

  }

}

​

function isValidMove(grid, row, col, num) {

  // Check if symbol exists in the row

  for (let i = 0; i < 9; i++) {

    if (grid[row][i] === num) {

      return false;

    }

  }

​

  // Check if symbol exists in the column

  for (let i = 0; i < 9; i++) {

    if (grid[i][col] === num) {

      return false;

    }

  }

​

  // Check if symbol exists in the 3x3 box

  let boxRow = Math.floor(row / 3) * 3;

  let boxCol = Math.floor(col / 3) * 3;

  for (let i = 0; i < 3; i++) {

    for (let j = 0; j < 3; j++) {

      if (grid[boxRow + i][boxCol + j] === num) {

        return false;

      }

    }

  }

​

  return true;

}

​

function giveHint() {

  // Simple hint system

  if (selectedCell) {

    let row = selectedCell.row;

    let col = selectedCell.col;

    if (originalGrid[row][col] === 0) {

      grid[row][col] = Math.floor(Math.random() * 9) + 1; // Random hint

      message = 'Here\'s a hint!';

    }

  }

}

​

function resetGame() {

  grid = JSON.parse(JSON.stringify(originalGrid)); // Reset grid to initial state

  message = 'Game reset!';

  selectedCell = null;

}

​

function displayMessage() {

  textSize(16);

  fill(0);

  text(message, 50, 490);

}

​

function checkWin() {

  // Check if all cells are filled correctly

  for (let row = 0; row < 9; row++) {

    for (let col = 0; col < 9; col++) {

      if (grid[row][col] === 0 || !isValidMove(grid, row, col, grid[row][col])) {

        return;

      }

    }

  }

  message = 'Congratulations, you solved it!';

}

​

// Sudoku generator with numbers corresponding to symbols

function generateSudoku() {

  return [

    [5, 3, 0, 0, 7, 0, 0, 0, 0],

    [6, 0, 0, 1, 9, 5, 0, 0, 0],

    [0, 9, 8, 0, 0, 0, 0, 6, 0],

    [8, 0, 0, 0, 6, 0, 0, 0, 3],

    [4, 0, 0, 8, 0, 3, 0, 0, 1],

    [7, 0, 0, 0, 2, 0, 0, 0, 6],

    [0, 6, 0, 0, 0, 0, 2, 8, 0],

    [0, 0, 0, 4, 1, 9, 0, 0, 5],

    [0, 0, 0, 0, 8, 0, 0, 7, 9],

  ];

}

​