factor_quadratic

COPY/// @func   factor_quadratic(b, c)
///
/// @desc   Returns a string of factors for any quadratic equation (ax^2+bx+c=0),
///         where a = 1 and b and c are integers. If it cannot be factored
///         with integer values only, the original quadratic is returned.
///
/// @param  {real}      b           value for the coefficient of x
/// @param  {real}      c           value for the constant
///
/// @return {string}    string of factors
///
/// GMLscripts.com/license

function factor_quadratic(b, c)
{
    var bb = b;
    var cc = c;
    if (b < 0) { bb = -b; }
    if (c < 0) { cc = -c; }
    var brk = 0;
    for (var a = -(max(bb, cc)); a <= max(bb, cc); a += 1) {
        for (var t = -(max(bb, cc)); t <= max(bb, cc); t += 1) {
            if (a * t == c && a + t == b) { brk = 1; break; }
        }
        if (brk == 1) { break; }
    }
    if (brk == 0) {
        if (b == 0) { b = ""; }
        else if (sign(b) > 0) { b = "+" + string(b); }
        else { b = string(b); }
        if (c == 0) { c = ""; }
        else if (sign(c) > 0) { c = "+" + string(c); }
        else { c = string(c); }
        return "x^2" + b + "x" + c;
    }
    if (a == 0) { a = ""; }
    else if (sign(a) > 0) { a = "+" + string(a); }
    else { a = string(a); }
    if (t == 0) { t = ""; }
    else if (sign(t) > 0) { t = "+" + string(t); }
    else { t = string(t); }
    return "(x" + a + ")(x" + t + ")";
}