Question

How to fill a 3x3 grid to be a valid Sudoku grid in Node.js

Answer 1

// To fill a 3x3 grid to be a valid Sudoku grid, you must ensure that each row, 
// column, and the 3x3 grid contains the numbers 1 through 9 without repetition.

function shuffleArray(array) {
    for (let i = array.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [array[i], array[j]] = [array[j], array[i]];
    }
}

// Function to fill the Sudoku grid
function fillSudokuGrid() {
    let numbers = [...Array(9).keys()].map(n => n + 1);

    // Shuffle the numbers randomly
    shuffleArray(numbers);

    // Fill the 3x3 grid row by row
    let grid = Array.from({ length: 3 }, () => Array(3).fill(0));
    let index = 0;

    for (let i = 0; i < 3; i++) {
        for (let j = 0; j < 3; j++) {
            grid[i][j] = numbers[index++];
        }
    }
    
    return grid;
}

// Function to print the grid
function printGrid(grid) {
    grid.forEach(row => console.log(row.join(' ')));
}

console.log("Generated 3x3 Sudoku Grid:");
printGrid(fillSudokuGrid());



/*
run:

Generated 3x3 Sudoku Grid:
6 2 9
4 1 7
3 5 8

*/

 

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