I've used https://paiza.io/en/projects/new?language=python3 for online testing basic text programs, and its worked for me. More on reddit.com

Thats OK, man. Those are hard questions and it doesn't mean anything about your general intelligence or your potential to be a successful programmer. Honestly, don't be too discouraged. You're on the right track. 1/4 is an extremely decent score for your first try at this kind of scenario, especially with the pressure of it being a quiz.. even more so if its timed. After one year of programming I'd have gotten a solid 0 out of 4. I guaran-fucking-tee it. As a Senior Engineer with 7 years of experience, I still definitely wouldn't bet on myself getting 100%. Not every interview will be this way. Some won't have this type of algorithm-solving at all. Moreover, when you see these types of quizzes you can rest easy that virtually no-one is getting 100%. In my experience interviewing candidates and setting up quizzes like these, everyone basically sucks at programming unless they know the answer beforehand (myself included). These types of tests are similar in results to university exams where the class gets a 40% average. I interviewed for a position 3 months ago that had similar first round questions. I worked my way through and got 2 out of the 4 solidly, with some decent progress and some failed tests on the other 2. I was invited in, and told they were especially excited about my high performance on the test. So that gives some perspective on how terribly people do on these types of tests, on average. (And that was for a senior engineering position.) Anyway, it sounds like I've been talking down the importance/relevance of these types of questions, and kinda saying "eh don't worry about it". But thats not entirely my intention. Obviously you sorta blew it, and want to improve on the next one. As far as advice goes: Study your ass off, and do tons of brain teaser problems like the ones on your quiz. I got that advice once and it seemed counter-intuitive to me.. Like how could just working on random brain-teasers make me better at solving different brain-teasers.. honestly my intuition still tells me that wouldn't work. The first thought I still have when failing these types of questions is "I can't solve this because I'm not good enough at thinking". Luckily, experience has shown me that is not true at all. Get the book "cracking the coding interview", or one like it, and get cracking. Start solving projecteuler questions.. those are great for building your logician/mathematical thinking chops. By the time you've finished doing 10% of the material you'll be blown away at how much easier other, unrelated brain-teaser problems seem. Last.. expect to see a steep upward curve in your performance on quizzes and interviews as you take them one after another. The first interview is gonna be the hardest. Good luck man! More on reddit.com

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like. More on reddit.com

[LANGUAGE: PostgreSQL] with recursive map as ( select array_agg(replace(input, '^', '.')) as map, max(length(input)) as max_j, max(row_num) as max_i, max(case when input like '%^%' then row_num end) as start_i, max(position('^' in input)) as start_j from day06 ), obstacles as ( select oi, oj from map cross join generate_series(1, max_i) as oi cross join generate_series(1, max_j) as oj where oi != start_i or oj != start_j union all select -1, -1 ), steps as ( select 0 as t, oi, oj, start_i as i, start_j as j, -1 as di, 0 as dj from map, obstacles union all select t + 1, oi, oj, case when next_tile = '.' then next_i else i end, case when next_tile = '.' then next_j else j end, case when next_tile = '.' then di else dj end, case when next_tile = '.' then dj else -di end from steps, map, lateral ( select i + di as next_i, j + dj as next_j, case when not (i + di between 1 and max_i) or not (j + dj between 1 and max_j) then null when i + di = oi and j + dj = oj then 'O' else substring(map.map[i + di], j + dj, 1) end as next_tile ) as new_pos where t < max_i * max_j and new_pos.next_tile is not null ), part1 as ( select count(distinct (i,j)) from steps where (oi, oj) = (-1, -1) ), part2 as ( select count(distinct (oi, oj)) from steps, map where t = max_i * max_j ) select * from part1, part2; More on reddit.com