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

const generateMatrix = (width, height) => {
    return Array.from({length: height}, () => Array.from({length: width}, () => Math.random() >= 0.5));
};

const nextCellState = (matrix, rowIdx, colIdx) => {
    const numberOfLiveNeighbors = [
        [-1, -1], [-1, 0], [-1, 1],
        [ 0, -1],          [ 0, 1],
        [ 1, -1], [ 1, 0], [ 1, 1],
    ].map((indexesDiff) => {
        const neighborRowIdx = rowIdx + indexesDiff[0];
        const neighborColIdx = colIdx + indexesDiff[1];
        return (neighborRowIdx < 0 || neighborColIdx < 0 || neighborRowIdx >= matrix.length || neighborColIdx >= matrix[0].length)
            ? 0
            : Number(matrix[neighborRowIdx][neighborColIdx])
    }).reduce((acc, item) => {
        return acc + item;
    }, 0);

    return numberOfLiveNeighbors === 3 || (matrix[rowIdx][colIdx] && numberOfLiveNeighbors === 2);
};

const applyStep = (matrix) => {
    return matrix.map((row, rowIdx) => row.map((col, colIdx) => nextCellState(matrix, rowIdx, colIdx)));
};

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

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

main();