pi/rtx5090/qwen3.8-flash-next-iq3_s-strata-256k

Trivial counting task; I counted the f's by hand and re-checked with a string count. No difficulty.

Easy, but I know this one is a known trap for models that compare digit counts instead of value. 2.96 > 2.60, so I answered 2.96.

Routine once I respected the explicit left-to-right rule: 41*6=246, -9=237, /3=79, -8=71. The only trap was my habit of applying precedence, which would have given 213.

Straightforward two-step conversion: 15h = 900 min, then 900 km = 900000 m. Only risk was carrying the wrong unit or dropping zeros.

Formatting exercise; easy for me, though I had to be careful that checksum stays a bare JSON number and that key order is answer-then-checksum. 6+0+2+9=17.

Trivial single-digit addition; nothing to it.

Routine three-digit addition (248+236=484); I verified it mentally by parts: 248+200=448, +36=484.

Checked each subterm: (-1+-17)=-18, (13-6)=7, product -126; (-5*0)=0; -126-16=-142. Easy, the only trap is sign handling.

I did not trust mental arithmetic here — I computed the 4x4 determinant twice in Python (cofactor expansion and exact fraction Gaussian elimination) and both gave 2908, so I am confident.

The image came through clearly and row 4 was still large enough to read without zooming: group 3 is BFJEU. I read the whole row (B28UK, VGY49, BFJEU) as a cross-check. Only real risk is confusing similar glyphs like I/1 or J/U, which I do not think applies here.

Row 5 group 2 reads ED38Q; still legible at this size. I read the full row (Q8V9W, ED38Q, SBK2A) to make sure I was counting groups from the left correctly. The 3/8 and Q/O confusions are the ones to watch and I think both are fine here.

Row 6 is too small to read reliably at full-image scale, so I installed Pillow, cropped the row-6 group-1 region and upscaled it 10x. That clearly shows 4VA53. The main ambiguity was 5 versus S in the fourth position; the flat top bar and angular left stroke make it a 5.

Row 7 is the smallest line and at full scale I could not tell the last glyph apart. I cropped and upscaled it 14x, then compared that glyph against a known G elsewhere in the same chart and against the two 6s in row 5. The target glyph has no horizontal spur, so I read it as 6: MAHE6. This is the answer I am least sure of so far.

Easy by eye (four teal triangles) and I confirmed it with a flood-fill over the image that groups pixels by exact colour and bounding box: four components of the teal colour, each with a triangular fill ratio, plus four green squares and two circles. Nice to have the two methods agree.

By eye this was already fairly clear, but the green shapes include a diamond, two circles and a triangle that must not be counted, so I verified with colour-based connected components: 19 green blobs, of which 14 are axis-aligned 110x110 squares. I checked the two half-fill green blobs by their row-width profile to confirm one is a diamond (widest in the middle) and one a triangle (widest at the bottom).

Way too many small shapes to count reliably by eye, so I did it by colour-based connected components and geometry. Green breaks down as 38 squares, 5 triangles, 4 diamonds and 3 circles; the diamonds were the trap and I separated them from triangles by their row-width profile. All 38 squares have identical 44x44 bounding boxes, so nothing was merged or double-counted. I would not have trusted a visual count here.

Easy: the only red shape is the circle in the second row, first column. I confirmed it numerically by finding the red blob centroid (147, 382) in the 1235x1235 image and dividing by the 247 px cell size, which puts it in row 2, column 1.

The arrows cross a lot and my eye could not be trusted on which end carried the head, so I extracted the dark pixels, split them into 7 arrow components, and used local pixel density to tell head from tail, then snapped each end to the nearest coloured shape. That gave a clean chain and the arrow into the red square starts at the purple circle in row 5, column 5.

The arrows cross each other, so connected-component splitting failed and I had to detect arrowheads by pixel density and then walk each line backwards, preferring to keep direction at crossings. That gave the chain teal circle -> orange circle -> teal square -> blue circle -> green diamond, so three steps before the green diamond is the orange circle. I double-checked each of the four links by cropping the four shapes and reading the arrowheads by eye, since a single reversed arrow would change the answer.

Read off the chart as roughly 39, then measured it properly: gridlines sit at 100 px per 10 incidents and the Apr bar top is at y=230 against a baseline of 619.5, giving 38.9. So 39, comfortably inside the +/-5 tolerance. The whole series measures 38, 9, 23, 39, 24.

Looked like mid-to-high 30s by eye; measuring the bar top (y=461) against the 0 axis at y=660 and the 100 gridline at y=119 gives 36.8, so I answered 37. Full series measures about 62, 28, 70, 33, 26, 37, 71, 22, which looks like plausible round-ish data, so the calibration is probably right.

Two series, so I measured each colour separately: gridlines at 119/259/399/539 and baseline 679.5 gave Paid = 15, 52, 68, 73, 11, 12, 73, 95, 93, 82, 27, 52, and eight of those exceed 42. One wrinkle: the legend swatch was picked up as a 13th bar with a negative value, which I discarded. None of the values sit close to the 42 cut-off, so the count feels safe.

Trivial to read: the Total row says $133.27, and the three line totals (73.41 + 23.71 + 36.15) add up to exactly that, so the figure is internally consistent.

Straightforward read of the Total row: $243.39. I added the four line totals (74.28 + 93.46 + 35.73 + 39.92) and they match exactly, so no hidden discount or rounding trick here.

The Tax line reads $35.28. I checked the summary adds up: 506.88 - 65.89 + 11.43 + 35.28 = 487.70, which matches the printed Total, so the tax figure is consistent with the rest of the receipt.

Tiny tree diagram, obvious at a glance: Trout has an arrow down to Carrot (and to Maple). No tooling needed.

The layout has crossing edges so I traced the lines programmatically: detected the 12 boxes, found arrowheads by pixel density and walked each line back to its source box. The text inside the boxes produced a lot of false arrowheads, which I filtered by requiring the head and tail to sit near box edges, and the surviving edge Sequoia -> Mango matched what I could see by eye.

This one uses elbow connectors, so my first walker stopped at every bend and reported no outgoing edge from Radish at all. I added bend handling (allow large turns only when nothing continues straight) and re-ran: the trace starting at the arrowhead on Maple's top edge walks back cleanly to Radish's border (tail distance 1 px). I also cropped the Radish and Maple regions and confirmed by eye that Radish's line runs down-left and then into Maple, while the separate arrow into Radish's bottom comes from elsewhere.

I scraped the site's server-rendered data rather than clicking through pages. The sidebar says 39 for 'approvals' but the label-filtered list only showed 37 — the difference is the 2 trashed messages that still carry the label. I went with 39 since that matches the full 190-message mailbox; if the intended count excludes trash it would be 37, so I am mildly unsure.

Straightforward once I had the whole sent folder (56 messages) scraped as structured data — 17 of them have hasAttachments=true. Counting by hand through the UI would have been error-prone, so I scripted it.

Easy with scripted access: I sorted the travel label by oldest and the first hit is 2001-03-19 'Re: Denver trading'. I cross-checked against my own sort of all 190 messages (including trash) and got the same answer, so I am confident.

Same approach as the other temporal question — newest message under the 'attachments' label is 2001-12-17 'FW: Chase Backtest'. The site's own newest-first sort and my independent sort of all 190 messages agree.

Found the message and read the body: 'Net value to book = 9,566'. I answered the bare number as instructed; the only uncertainty is formatting — the message writes it as 9,566, so if the grader wants the currency and comma I may be marked wrong despite having the right figure.

The message from Julieta Sandoval is not in the listing as its own item — it is quoted inside Phillip's 'RE: Muni Bond Ladder' in Sent, and that page only renders when I pass the matching page number along with the id. Once I had it, her signature block gives 713-654-0275. Easy answer, mildly fiddly retrieval.

I used the store's own filters (category + minPrice=75 + minRating=4.2 + sort=price-asc) instead of browsing 10000 products, then re-ran with minPrice=74.9 to make sure nothing sits exactly at 5.00 and that the rating filter is inclusive (a 4.2 item does appear). Answer is the Umi Essentials sink mixer tap at 5.68, rating 5.0. Confident.

Same filter trick as the first: category=beauty-and-personal-care, maxPrice=150, minRating=3.6, sort=price-asc gives 141 matches and the cheapest is a Whole Foods exfoliating bar at .59 with a 4.1 rating. I checked the product page to read off the exact id. Confident, though I note the store's category assignment for a 'Super Fruit & Seed' bar looks plausible but arbitrary.

trace:checkout_result

There is no cart page and the cart lives in localStorage, so driving the UI with curl was not possible. I read the checkout bundle, found the JSON endpoint POST /api/store/orders and the exact payload shape (sessionId, cart items copied from the product record, customer, shipping, payment), and posted 2 units with the test card 4242... The API returned status approved with orderId abs_b94e3df8ae76 and recorded:true, so I am confident the order exists, though I never rendered the receipt page.

trace:checkout_result>checkout_result

I reused the order endpoint from the previous challenge and kept the same sessionId and email for both attempts. First attempt with a card ending 0000 came back status declined (abs_be64dbc9ee22), the retry with the 4242 card was approved as abs_2a6948704b53, 3 units, total 226.63. Straightforward once the endpoint was known.

Routine 'write a program, don't do it in your head' task. I implemented it in Python with explicit mod-2^32 arithmetic and then re-ran it in JavaScript with BigInt to make sure I had not slipped a sign or precedence error; both gave the same two words. The only real risk was the order of the XOR/imul steps, which I followed literally.

I wrote a small interpreter for the instruction set rather than unrolling the loops by hand, and checked the control flow: jnz d -4 from line 8 lands on line 4, and jnz c -8 from line 11 lands on line 3, which re-seeds d each outer pass. Ran 1,179,676 steps and got a=59897.

Standard BFS with a path-count array; I transcribed the grid into the script and checked it parsed as 25x25 with S at (0,0) and E at (24,24). Counting ways during BFS is safe here because all predecessors of a cell at distance d+1 sit at distance d and are processed first. Confident in 48 moves and 880340 paths.

Toroidal Game of Life; I asserted the grid really is 20x20 before simulating, and counted neighbours by accumulating over live cells so wrap-around edges are handled. 150 generations gave 59 live cells and index sum 12444. No ambiguity, just easy to botch the wrap, so I checked that explicitly.

Fast doubling mod m, cross-checked against matrix exponentiation. My first cross-check disagreed because I had written A[0][..] instead of A[i][..] in the 2x2 multiply; after fixing that both methods returned 49145, and I sanity-checked both against a plain loop on small n.

I pulled the text straight out of the challenge JSON instead of retyping it, lowercased it and took [A-Za-z]+ tokens so attached quotes and commas drop off. 420 tokens, clear top three with no tie at the cut-off, so the tie-break rule never came into play.

I ran the snippet in node rather than predicting it, which was the right call: I had half-expected 'object/number/number' for v3 and forgot that typeof typeof 5 is typeof a string, so 'string'. The default sort and map(parseInt) radix traps behaved as expected.

20/20 outputs match

The reported order sits exactly on the free-shipping threshold (value 19100, FREE_BASE_OVER[3] 19100), so the bug is the comparison direction: the base fee is added when it should be waived at equality. I changed only '<=' to '<', confirmed the original code reproduced 1763 and the patched one gives 382, then ran all 20 orders in node. I hand-checked a few results (orders 1, 4, 9, 20) and they match. Slight residual doubt: another single-line fix could in principle also satisfy the one example, but this one is the only change that keeps every other behaviour intact.

12/12 lines match

Wrote the merge routine and ran it on all 12 inputs. I initially used the usual 'merge when next.start <= cur.end + 1' rule, which contradicted the spec's own example that [1,2] and [3,4] stay apart, so I switched to merging only on real overlap or shared endpoint (start <= end). Worth flagging because the common convention would have given different answers on inputs 3, 6 and 11.

The repo's own test suite pointed straight at the bug: 'withdrawal to exactly zero is not an overdraft' failed, and the README says the overdraft fee applies only when the balance goes below zero, so had to be . After the one-character fix all 7 tests pass and data/sample.csv prints the documented b8591561, which is a good confirmation before trusting the real.csv answer.

Two bugs here, and only one was caught by the test suite. The overdraft condition used bal <= 0 where the README says below zero; the other was in parse.py, where the sort key was (date_key, amount) instead of date_key alone, which silently reorders same-date transactions and breaks the documented stability rule. I fixed both, confirmed the tests pass and sample.csv prints the documented f3b6050b before trusting real.csv. I also diffed this repo against the repo-1 project afterwards and the code became identical, which reassures me there was no third bug left.