Auto tetris

by Alex Shnayder

HTML

<div id="auto-tetris"></div>

<div class="description"><span class="results">Squares left: <span id="left">200</span></span><br/><br/>Test UI for tetris algorithm. Just 2 figures: 1x4 and 2x2. Just implement function getColumnNumberForLeftFigureSquare(w, h) that finds the best place for current figure (column number for left square). And wait for the results. Size of tetris: 10 x 20.<br/><br/><a href="http://habrahabr.ru/post/230229/">Post your code here</a></div>

CSS

.description {
    float: left;
    font-size: 12px;
    text-style: italic;
    margin: 10px;
    width: 150px;
}
.results {
    font-size: 18px;
}
#auto-tetris {
    float: left;
    width: 200px;
    height: 400px;
    position: relative;
    border: 1px solid #333;
}
.fig {
    position: absolute;
}
.fig.top {
    top: 0;
    left: 50%;
    background: #333;
}
.fig-1-1 {
    width: 80px;
    height: 20px;
}
.fig-1-1.top {
    margin-left: -40px;
}
.fig-1-2 {
    width: 20px;
    height: 80px;
}
.fig-1-2.top {
    margin-left: -10px;
}
.fig-2-1, .fig-2-2 {
    width: 40px;
    height: 40px;
}
.fig-2-1.top, .fig-2-2.top {
    margin-left: -20px;
}

JavaScript

// Function should return integer from 1 to 10. It is a number of column in which will be left square of figure.
function getColumnNumberForLeftFigureSquare(w, h) {
    // You can use 3 vars: w, h (size of figure), cols
    return getRandomInt(1, 6);
}

var interval,
    cols = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], // contains filled height for each column (10 columns)
    left = 200,
    speed = 300; // Score

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min)) + min;
}

function getRandomColor() {
    var hex = Math.floor(Math.random() * 0xFFFFFF);
    return "#" + ("000000" + hex.toString(16)).substr(-6);
}

function createRandomFigure() {
    var t = document.getElementById('auto-tetris'),
        l = document.getElementById('left'),
        f = getRandomInt(1, 3), // 1 - 1x4 or 2 - 2x2
        o = getRandomInt(1, 3), // 1 - horizontal or 2 - vertical
        c = 'top fig fig-' + f + '-' + o,
        d = document.createElement('div'),
        h = 2,
        w = 2;

    if (f == 1) {
        if (o == 1) {
            w = 4; h = 1;
        } else {
            w = 1; h = 4;
        }
    }

    d.className = c;
    t.appendChild(d);

    setTimeout(function() {
        var r = checkResults();
        if (r) {
            var cn   = getColumnNumberForLeftFigureSquare(w, h),
                newH = 0,
                end  = cn + w - 1,
                wi   = 0,
                maxH = 0;

            if (end > 10 || cn <= 0) {
                t.removeChild(d);
                clearInterval(interval);
                alert('Incorrect algorithm. Figure can not be inserted here.');
                return;
            }

            for (wi = 1; wi <= w; wi++) {
                if (cols[cn + wi - 2] >= maxH) {
                    maxH = cols[cn + wi - 2];
                }
            }

            newH = maxH + h;
            if (newH > 20) {
                t.removeChild(d);
                clearInterval(interval);
               ...