代码如下

$f = 0
$tmp = Array.new
$res = Array.new

def combination_sum3(k, n)

if (k > 9) or (k < 1) or (n > 9) or (n < 1)
    return $res
end
f = $f + 1

if (n < (2 * f + k - 1  ) * k / 2) && (k != 1 )
    return $res
end

if k != 1
    for i in f .. n/k do
        $f = i
        $tmp << i
        combination_sum3(k - 1, n - i)
        $tmp.pop
    end
elsif n > $tmp[-1]
    $tmp << n
    $res << $tmp.clone
    $tmp.pop
end

end

但是最后submit时出错

Runtime Error Message: Line 48: in `block in _driver'
小白，初用LeetCode和segmentfault