Word wrap to X lines instead of maximum width (Least raggedness)

Question

Does anyone know a good algorithm to word wrap an input string to a specified number of lines rather than a set width. Basically to achieve the minimum width for X lines.

Answer 1

I converted the C# accepted answer to JavaScript for something I was working on. Posting it here might save someone a few minutes of doing it themselves.

function WrapTextWithLimit(text, n) {
    var words = text.toString().split(' ');
    var cumwordwidth = [0];
    words.forEach(function(word) {
        cumwordwidth.push(cumwordwidth[cumwordwidth.length - 1] + word.length);
    });
    var totalwidth = cumwordwidth[cumwordwidth.length - 1] + words.length - 1;
    var linewidth = (totalwidth - (n - 1.0)) / n;
    var cost = function(i, j) {
        var actuallinewidth = Math.max(j - i - 1, 0) + (cumwordwidth[j] - cumwordwidth[i]);
        return (linewidth - actuallinewidth) * (linewidth - actuallinewidth);
    };
    var best = [];
    var tmp = [];
    best.push(tmp);
    tmp.push([0.0, -1]);
    words.forEach(function(word) {
        tmp.push([Number.MAX_VALUE, -1]);
    });
    for (var l = 1; l < n + 1; ++l)
    {
        tmp = [];
        best.push(tmp);
        for (var j = 0; j < words.length + 1; ++j)
        {
            var min = [best[l - 1][0][0] + cost(0, j), 0];
            for (var k = 0; k < j + 1; ++k)
            {
                var loc = best[l - 1][k][0] + cost(k, j);
                if (loc < min[0] || (loc === min[0] && k < min[1])) {
                    min = [loc, k];
                }
            }
            tmp.push(min);
        }
    }
    var lines = [];
    var b = words.length;
    for (var p = n; p > 0; --p) {
        var a = best[p][b][1];
        lines.push(words.slice(a, b).join(' '));
        b = a;
    }
    lines.reverse();
    return lines;
}