Game of life - v.02

game-of-life-v02.js

// https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life

const populate = (matrix) => {
    return matrix.map(row => row.map(_ => Math.random() >= 0.5));
};

const createMatrix = (width, height) => {
    const matrix = Array.from(new Array(height)).map(_ => Array.from(new Array(width)));
    return populate(matrix);
};

const printMatrix = (matrix) => {
    matrix.forEach((row) => {
        console.log(row.map(item => item ? '*' : 'o').join(' '));
    });
};

const isNeighbour = (rowIdx, colIdx, i, j) => {
    return (i <= rowIdx + 1 && i >= rowIdx - 1) &&
        (j <= colIdx + 1 && j >= colIdx - 1) &&
        (!(i === rowIdx && j === colIdx));
};

const getLiveNeighboursCount = (matrix, rowIdx, colIdx) => {
    return matrix.reduce((acc, row, i) => {
        return acc + row.filter((_, j) => isNeighbour(rowIdx, colIdx, i, j))
                        .reduce((rowAcc, item) => rowAcc + (item ? 1 : 0), 0);
    }, 0);
};

const apply = matrix => matrix.map((row, i) => row.map((item, j) => {
    const count = getLiveNeighboursCount(matrix, i, j);
    return count === 3 || (item && count === 2);
}));

const main = () => {
    const matrix = createMatrix(4, 4);
    printMatrix(matrix);
    console.log();
    printMatrix(apply(matrix));
};

main();