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#!/usr/bin/env python
"""IOL-AI 2026 submission -- International Linguistics Olympiad solver.
Design notes (the eval sandbox is unforgiving, so these matter):
* HARD 30-MINUTE LIMIT. A killed process means no score at all, so the script
is structured as a monotonically-improving pipeline: it writes a complete,
correctly-shaped submission.csv *before* the model is even loaded, then
overwrites it after every improvement. Any crash or timeout leaves the best
result reached so far on disk.
* ALIGNMENT IS EVERYTHING. Each row is a problem block with N numbered items
and `pred` must be a JSON list of exactly N answers, in order. One missing
line shifts every later answer and zeroes the whole block on both metrics.
So N is detected from the query and the model output is force-fitted to it.
* NEVER EMIT AN EMPTY STRING. The final score is a geometric mean of exact
match and chrF, so an empty answer scores zero on both. A wrong guess is
strictly better than a blank.
* Environment is transformers 4.44.1 / torch 2.4.0 / autoawq on a 16GB T4
(fp16 only, no bf16, no flash-attn), with no internet.
"""
import os
import re
import json
import time
import unicodedata
from collections import Counter, defaultdict
T0 = time.time()
# The platform allows 30 minutes. Reserve a margin for model load overhead we
# can't predict and for the final write; being 60s early costs a little
# accuracy, being 1s late costs the entire submission.
TIME_LIMIT = float(os.environ.get("IOL_TIME_LIMIT", "1800"))
SAFETY = float(os.environ.get("IOL_SAFETY", "150"))
DEADLINE = T0 + TIME_LIMIT - SAFETY
TEST_CSV = os.environ.get("IOL_TEST_CSV", "/tmp/data/test.csv")
OUT_CSV = os.environ.get("IOL_OUT_CSV", "submission.csv")
MODEL_ID = os.environ.get("IOL_MODEL", ".")
WANT_EXPLANATION = os.environ.get("IOL_EXPLAIN", "1") == "1"
MAX_NEW = int(os.environ.get("IOL_MAXNEW", "900")) # reasoning budget/item
MAX_SAMPLES = int(os.environ.get("IOL_MAXSAMPLES", "8")) # self-consistency cap
# BASELINE REPLICATION MODE. The organizers' reference script reaches exact match
# 0.0729 on the hidden set with THESE EXACT WEIGHTS; our best is 0.0333. Before
# adding anything else we need to know whether that number is reproducible by us
# at all. This mode replicates their script literally -- trivial prompt, no CoT,
# 512 tokens, batch 1 (no padding at all), naive line split, NO forcing to N --
# and changes exactly one thing: repetition_penalty=1.0, our one proven fix.
BASELINE_MODE = os.environ.get("IOL_BASELINE", "1") == "1" # v8: ON by default
# Lower than the usual 0.7: samples only earn a vote by agreeing with each
# other, so keeping them near the greedy mode makes agreement meaningful.
SAMPLE_TEMP = float(os.environ.get("IOL_TEMP", "0.5"))
os.environ.setdefault("HF_HUB_OFFLINE", "1")
os.environ.setdefault("TRANSFORMERS_OFFLINE", "1")
os.environ.setdefault("TOKENIZERS_PARALLELISM", "false")
# Reduce allocator fragmentation: at batch 4 the T4 has only ~2GB spare.
os.environ.setdefault("PYTORCH_CUDA_ALLOC_CONF", "expandable_segments:True")
def log(msg):
print(f"[{time.time() - T0:7.1f}s] {msg}", flush=True)
def left():
return DEADLINE - time.time()
# ===========================================================================
# Item-count detection (validated: 98.4% of Linguini items land in
# correctly-sized blocks)
# ===========================================================================
_LINE_NUM = re.compile(r"^[ \t]*(\d{1,3})[.)\]]", re.M)
_PAREN_NUM = re.compile(r"\((\d{1,3})\)")
_RANGE = re.compile(r"\(?(\d{1,3})\s*(?:[-–—]|to)\s*(\d{1,3})\)?")
_LINE_LETTER = re.compile(r"^[ \t]*([A-Z])[.)\]]\s", re.M)
_PAREN_LETTER = re.compile(r"\(([A-Z])\)")
def detect_n_items(query, task_type="", context=""):
"""How many numbered sub-items this problem asks for. Never < 1."""
q = query or ""
line_nums = [int(m) for m in _LINE_NUM.findall(q)]
paren_nums = [int(m) for m in _PAREN_NUM.findall(q)]
range_n = 0
for a, b in _RANGE.findall(q):
a, b = int(a), int(b)
if 0 < b - a < 60:
range_n = max(range_n, b - a + 1)
cand = max(len(set(line_nums)), len(set(paren_nums)))
if range_n and cand and range_n != cand:
# A stated range ("items 1-4") can disagree with the markers actually
# present; the markers are what we have to answer, so they win.
return cand
cand = max(cand,
len(set(_LINE_LETTER.findall(q))),
len(set(_PAREN_LETTER.findall(q))))
n = max(range_n, cand)
if n > 1:
return n
# Unnumbered "Translate into X:" followed by one item per line.
lines = [l.strip() for l in q.splitlines() if l.strip()]
if len(lines) > 1:
head = lines[0]
body = lines[1:] if head.endswith((":", ".")) else lines
if body:
return len(body)
# Bare instruction ("Determine the correct correspondences."): items are in
# the shared context (this is the match_letters shape).
if context:
c_nums = len(set(int(m) for m in _LINE_NUM.findall(context)))
if c_nums > 1:
return c_nums
c_lets = len(set(_LINE_LETTER.findall(context)))
if c_lets > 1:
return c_lets
return max(n, 1)
# ===========================================================================
# Output parsing / repair
# ===========================================================================
_STRIP_PREFIX = re.compile(r"^\s*(?:\(?\d{1,3}\)?[.):\]]\s*|[-*•]\s+)")
_FENCE = re.compile(r"^```[a-zA-Z]*\s*$")
_CHATTY = re.compile(
r"^\s*(?:here (?:are|is)\b|answers?\s*:?\s*$|explanation\b|note\b|okay\b|"
r"solution\b|reasoning\b|analysis\b|translations?\s*:?\s*$|the answers?\b|"
r"let me\b|first,|so,|therefore\b|thus\b)",
re.I,
)
def clean_line(s):
s = s.strip()
s = _STRIP_PREFIX.sub("", s)
s = s.strip().strip("`").strip()
if len(s) >= 2 and s[0] == s[-1] and s[0] in "\"'“”":
s = s[1:-1].strip()
# "word | gloss" answer lines: keep the side being asked for is ambiguous,
# so keep the whole line -- chrF still gives partial credit.
return s.strip()
def extract_item_sources(query, n):
"""The source text of each numbered item, used as a last-resort fallback.
A blank scores zero on both metrics; echoing the item's own source string is
strictly better, and on transcription / fill-the-blank tasks the source and
the target share a lot of characters, so it collects real chrF credit.
"""
q = query or ""
out = []
for ln in q.splitlines():
s = ln.strip()
if not s:
continue
m = re.match(r"^\(?(\d{1,3})\)?[.):\]]\s*(.+)$", s)
if m:
out.append(m.group(2).strip())
if not out:
lines = [l.strip() for l in q.splitlines() if l.strip()]
if len(lines) > 1 and lines[0].endswith((":", ".")):
out = lines[1:]
# "form | gloss" items: the left side is the thing being asked about.
out = [o.split("|")[0].strip() if "|" in o else o for o in out]
out = [o for o in out if o]
while len(out) < n:
out.append(out[-1] if out else "?")
return out[:n]
def parse_answers(text, n, fallback=None):
"""Raw model output -> exactly n non-empty answers."""
if not text:
return list(fallback[:n]) if fallback else ["?"] * n
# Prefer the explicit final block the prompt asks for.
m = None
for m2 in re.finditer(r"(?:^|\n)\s*(?:final\s+)?answers?\s*:\s*\n?", text, re.I):
m = m2
body = text[m.end():] if m else text
numbered, raw = [], []
for ln in body.splitlines():
if _FENCE.match(ln):
continue
mm = re.match(r"^\s*\(?(\d{1,3})\)?[.):\]]\s*(.+)$", ln.strip())
if mm:
val = clean_line(mm.group(2))
if val and not _CHATTY.match(val):
numbered.append((int(mm.group(1)), val))
c = clean_line(ln)
if c and not _CHATTY.match(c):
raw.append(c)
# If the model numbered its answers, trust those labels for placement.
if len(numbered) >= n:
by_label = {}
for lab, val in numbered:
by_label[lab] = val # last write wins (models restate)
labs = sorted(by_label)
if len(labs) >= n:
return [by_label[l] for l in labs[:n]]
return fit_to_n(raw, n, fallback)
def fit_to_n(items, n, fallback=None):
items = [i for i in items if i and i.strip()]
if len(items) > n:
# Take the LAST n. The prompt asks for reasoning first and the answers
# last, so when there is no ANSWERS: marker to slice on, the tail is the
# answer block and the head is reasoning prose.
items = items[-n:]
while len(items) < n:
if fallback and len(items) < len(fallback):
items.append(fallback[len(items)])
else:
items.append(items[-1] if items else "?")
return items[:n]
def norm(s):
s = unicodedata.normalize("NFC", (s or "").strip().lower())
s = re.sub(r"\s+", " ", s)
return s.strip(" .!?;:,")
# ===========================================================================
# chrF (inline, dependency-free) -- used only to pick the most "central"
# candidate when self-consistency voting has no majority. sacrebleu is not
# guaranteed to be importable inside the sandbox.
# ===========================================================================
def _ngrams(s, k):
s = re.sub(r"\s+", "", s)
return Counter(s[i:i + k] for i in range(len(s) - k + 1)) if len(s) >= k else Counter()
def chrf_sim(hyp, ref, order=6, beta=2.0):
if not hyp or not ref:
return 0.0
ps, rs = [], []
for k in range(1, order + 1):
h, r = _ngrams(hyp, k), _ngrams(ref, k)
if not h or not r:
continue
overlap = sum((h & r).values())
ps.append(overlap / max(1, sum(h.values())))
rs.append(overlap / max(1, sum(r.values())))
if not ps:
return 0.0
p, r = sum(ps) / len(ps), sum(rs) / len(rs)
if p + r == 0:
return 0.0
b2 = beta * beta
return (1 + b2) * p * r / (b2 * p + r)
def vote(cands, anchor=None):
cands = [c for c in cands if c and c.strip()]
if anchor is None:
anchor = cands[0] if cands else "?"
if len(cands) < 2:
return anchor
groups = defaultdict(list)
for c in cands:
groups[norm(c)].append(c)
anchor_support = len(groups.get(norm(anchor), []))
best_key, best_n = None, 0
for k, v in groups.items():
if len(v) > best_n:
best_key, best_n = k, len(v)
# At pool size 2 (greedy + 1 sample), the only meaningful signal is a
# *disagreement*: sample diverges from greedy. We can't get independent
# corroboration with a single sample, so require >=2 non-anchor samples
# to actually agree with each other before overriding — not just with
# the anchor's absence.
non_anchor_groups = {k: v for k, v in groups.items() if k != norm(anchor)}
if non_anchor_groups:
alt_key, alt_n = max(non_anchor_groups.items(), key=lambda kv: len(kv[1]))
if alt_n >= 2 and alt_n > anchor_support:
return Counter(non_anchor_groups[alt_key]).most_common(1)[0][0]
return anchor
_OPT_LINE = re.compile(r"^[ \t]*([A-Za-z])[.)]\s+(.+)$", re.M)
_ITEM_LINE = re.compile(r"^[ \t]*(\d{1,3})[.)]\s+(.+)$", re.M)
def parse_matching_block(context):
"""For match_letters: the numbered items and the lettered options."""
items = [(int(a), b.strip()) for a, b in _ITEM_LINE.findall(context or "")]
opts = [(a, b.strip()) for a, b in _OPT_LINE.findall(context or "")]
seen = set()
items = [x for x in items if not (x[0] in seen or seen.add(x[0]))]
seen = set()
opts = [x for x in opts if not (x[0] in seen or seen.add(x[0]))]
return items, opts
def best_assignment(score):
"""Max-weight one-to-one assignment. scipy if present, else greedy+swaps."""
n, m = len(score), len(score[0])
try:
from scipy.optimize import linear_sum_assignment
import numpy as _np
r, c = linear_sum_assignment(-_np.array(score))
return list(c)
except Exception:
pass
used, out = set(), [0] * n
order = sorted(range(n), key=lambda i: -(max(score[i]) - sorted(score[i])[-2]
if m > 1 else 0))
for i in order:
j = max((j for j in range(m) if j not in used),
key=lambda j: score[i][j], default=0)
used.add(j)
out[i] = j
for _ in range(4): # local 2-swaps
improved = False
for a in range(n):
for b in range(a + 1, n):
cur = score[a][out[a]] + score[b][out[b]]
alt = score[a][out[b]] + score[b][out[a]]
if alt > cur + 1e-9:
out[a], out[b] = out[b], out[a]
improved = True
if not improved:
break
return out
def repair_bijection(answers):
"""match_letters answers are usually a permutation of the option letters.
When every answer is a single letter and there are as many items as
distinct letters available, duplicates are certainly wrong. Reassign the
duplicated slots to the unused letters. Strictly guarded so it is a no-op
on anything that isn't this shape.
"""
if len(answers) < 3:
return answers
if not all(re.fullmatch(r"[A-Z]", a or "") for a in answers):
return answers
n = len(answers)
universe = [chr(ord("A") + i) for i in range(n)]
if len(set(answers)) == n:
return answers
unused = [l for l in universe if l not in set(answers)]
if not unused:
return answers
seen, out = set(), []
for a in answers:
if a in seen and unused:
out.append(unused.pop(0))
else:
seen.add(a)
out.append(a)
return out
# ===========================================================================
# Prompting
# ===========================================================================
SYSTEM = (
"You are a gold medallist at the International Linguistics Olympiad.\n"
"Each problem gives data from a language you have never seen. Everything "
"you need is in the problem itself; no outside knowledge is required or "
"allowed.\n"
"Method: line up the given examples, segment the words, identify the "
"recurring morphemes and the rules that order them, check your rules "
"against EVERY example, then apply them to the items asked for.\n"
"Be concise while reasoning. Then output a final block that begins with a "
"line containing exactly ANSWERS: followed by one answer per line, in the "
"order asked, with no numbering, no commentary and no blank lines.\n"
"Give your best guess for every item. Never leave one blank."
)
# Exact match is half the score, so the answer's *form* matters as much as its
# content. test.csv states the task type, so say precisely what a well-formed
# answer looks like. Unknown/absent types simply get no hint.
TASK_HINTS = {
"translation": "Each answer is the translation alone -- no source text, no "
"gloss, no notes, no quotation marks.",
"match_letters": "Each answer is a single capital letter identifying the "
"match for that numbered item. Every letter is used "
"exactly once, so no letter may repeat.",
"fill_blanks": "Each answer is only the missing form that belongs in that "
"blank -- not the whole line, not the gloss.",
"text_to_num": "Each answer is written in digits only (e.g. 111).",
"num_to_text": "Each answer is the number written out in the problem "
"language, words only.",
}
def build_prompt(row, n):
hint = TASK_HINTS.get((row.get("task_type") or "").strip().lower(), "")
return (
f"{row['context'].strip()}\n\n{row['query'].strip()}\n\n"
f"There are exactly {n} item{'s' if n != 1 else ''} to answer."
+ (f" {hint}" if hint else "") +
f"\nAfter your reasoning, write ANSWERS: on its own line and then exactly "
f"{n} line{'s' if n != 1 else ''}, one answer per item, in order."
)
EXPLAIN_SYSTEM = (
"You explain International Linguistics Olympiad solutions to a human judge. "
"Given a problem and the answers produced, state the key rules of the "
"language that justify them: the relevant morphemes, word order and any "
"sound changes. Be specific and concise (2-4 sentences or a few short "
"bullets). Do not restate the reasoning as a stream of thought."
)
def build_explain_prompt(row, answers):
return (
f"{row['context'].strip()}\n\n{row['query'].strip()}\n\n"
f"Answers given:\n" + "\n".join(f"- {a}" for a in answers) +
"\n\nBriefly explain the linguistic rules behind these answers."
)
# ===========================================================================
# Main
# ===========================================================================
def dev_score(preds):
"""Offline diagnostic: score against a gold file when IOL_GOLD is set.
Never runs on the platform (the answers are hidden, so the variable is
unset there); it exists so one benchmark run reveals the whole learning
curve -- greedy, then after each self-consistency pass -- instead of a
single final number.
"""
gold_path = os.environ.get("IOL_GOLD")
if not gold_path or not os.path.exists(gold_path):
return
try:
import ast
import pandas as pd
g = pd.read_csv(gold_path, dtype=str)
ems, cfs = [], []
for _, r in g.iterrows():
gold = ast.literal_eval(r["answer"])
p = preds.get(str(r["id"]), [])
p = list(p)[:len(gold)] + [""] * max(0, len(gold) - len(p))
for gi, pi in zip(gold, p):
alts = gi if isinstance(gi, (list, tuple)) else [gi]
alts = [str(a) for a in alts]
ems.append(1.0 if any(pi.strip() == a.strip() for a in alts) else 0.0)
cfs.append(max(chrf_sim(pi, a) for a in alts))
em = sum(ems) / max(1, len(ems))
cf = sum(cfs) / max(1, len(cfs))
log(f" [dev] EM={em:.4f} chrF~={cf:.4f} score~={(em * cf) ** 0.5:.4f} "
f"over {len(ems)} items")
except Exception as e:
log(f" [dev] scoring failed: {type(e).__name__}: {e}")
def write_submission(path, ids, preds, explanations=None):
import pandas as pd
rows = []
for i in ids:
rec = {"id": i, "pred": json.dumps(preds[i], ensure_ascii=False)}
if explanations is not None:
rec["explanation"] = explanations.get(i, "")
rows.append(rec)
pd.DataFrame(rows).to_csv(path, index=False)
def main():
import pandas as pd
df = pd.read_csv(TEST_CSV, dtype=str).fillna("")
ids = [str(x) for x in df["id"].tolist()]
ns = [detect_n_items(r.get("query", ""), r.get("task_type", ""), r.get("context", ""))
for _, r in df.iterrows()]
total_items = sum(ns)
log(f"loaded {len(df)} problems, {total_items} items "
f"(min={min(ns)} max={max(ns)} mean={total_items / len(ns):.1f})")
srcs = {i: extract_item_sources(r.get("query", ""), n)
for i, (_, r), n in zip(ids, df.iterrows(), ns)}
# --- 1. Baseline submission on disk before anything can go wrong --------
preds = {i: list(srcs[i]) for i in ids}
explanations = {i: "" for i in ids} if WANT_EXPLANATION else None
write_submission(OUT_CSV, ids, preds, explanations)
log(f"wrote placeholder {OUT_CSV} ({len(ids)} rows)")
# --- 2. Load model -----------------------------------------------------
import torch
from transformers import (AutoTokenizer, AutoModelForCausalLM,
StoppingCriteria, StoppingCriteriaList)
class Deadline(StoppingCriteria):
"""Abort generation on wall-clock, checked every token.
Without this the budget is only checked between batches, so a batch
started near the limit runs past it and the platform kills the process.
"""
def __init__(self, stop_at):
self.stop_at = stop_at
def __call__(self, input_ids, scores, **kw):
return time.time() > self.stop_at
log("loading tokenizer/model ...")
tok = AutoTokenizer.from_pretrained(MODEL_ID, trust_remote_code=True)
if tok.pad_token is None:
tok.pad_token = tok.eos_token
tok.padding_side = "left"
# Pin every layer to the GPU. device_map="auto" is free to spill layers to
# CPU when it thinks VRAM is tight, and a couple of offloaded layers make
# generation ~100x slower without any error -- the worst kind of failure
# here. Falling back to "auto" only if the explicit placement fails.
def _load(dev_map):
# transformers 4.44 (the sandbox) wants torch_dtype=; 5.x renamed it to
# dtype=. Accept either so the same file runs in both.
try:
return AutoModelForCausalLM.from_pretrained(
MODEL_ID, torch_dtype=torch.float16, device_map=dev_map,
trust_remote_code=True).eval()
except TypeError:
return AutoModelForCausalLM.from_pretrained(
MODEL_ID, dtype=torch.float16, device_map=dev_map,
trust_remote_code=True).eval()
try:
model = _load({"": 0} if torch.cuda.is_available() else "auto")
except Exception as e:
log(f"pinned load failed ({type(e).__name__}: {e}); falling back to auto")
model = _load("auto")
devs = set(str(p.device) for p in model.parameters())
log(f"model ready on {sorted(devs)} ({left():.0f}s of budget left)")
if any(d.startswith("cpu") or d == "meta" for d in devs):
log("WARNING: part of the model is off-GPU; generation will be very slow")
if torch.cuda.is_available():
log(f" VRAM allocated {torch.cuda.memory_allocated()/1e9:.2f} GB / "
f"{torch.cuda.get_device_properties(0).total_memory/1e9:.1f} GB")
prompts = []
for (_, r), n in zip(df.iterrows(), ns):
if BASELINE_MODE:
msgs = [{"role": "system", "content":
"You solve International Linguistics Olympiad problems. "
"Answer every numbered item. Put each answer on its own line, "
"in order, with no numbering and no extra text."},
{"role": "user", "content":
f"{r['context'].strip()}\n\n{r['query'].strip()}"}]
else:
msgs = [{"role": "system", "content": SYSTEM},
{"role": "user", "content": build_prompt(r, n)}]
prompts.append(tok.apply_chat_template(msgs, tokenize=False,
add_generation_prompt=True))
batch_size = 1 if BASELINE_MODE else int(os.environ.get("IOL_BATCH", "4"))
def generate(texts, max_new, sample, temp=0.7):
"""Batched generation with OOM backoff. Returns list of strings."""
nonlocal batch_size
out = [""] * len(texts)
order = sorted(range(len(texts)), key=lambda i: len(texts[i]))
i = 0
while i < len(order):
if left() < 25:
log(" out of time inside generate(); returning partial")
break
idx = order[i:i + batch_size]
chunk = [texts[j] for j in idx]
try:
enc = tok(chunk, return_tensors="pt", padding=True,
truncation=True, max_length=6144).to(model.device)
# repetition_penalty=1.0 EXPLICITLY. Qwen2.5-14B-Instruct-AWQ
# ships generation_config.json with repetition_penalty=1.05,
# and unlike temperature/top_p/top_k (which greedy ignores, and
# which transformers warns about) a repetition penalty IS
# applied under greedy decoding -- silently, with no warning.
# 34% of the public gold answers repeat a letter 3+ times
# (agglutinative morphology like 'ɨmpʼuhurʼu'), so a 5% penalty
# pushes the model off exactly the strings we need.
kw = dict(max_new_tokens=max_new, pad_token_id=tok.pad_token_id,
repetition_penalty=1.0,
stopping_criteria=StoppingCriteriaList(
[Deadline(DEADLINE - 10)]))
if sample:
kw.update(do_sample=True, temperature=temp, top_p=0.95)
else:
kw.update(do_sample=False)
with torch.no_grad():
o = model.generate(**enc, **kw)
for k, j in enumerate(idx):
out[j] = tok.decode(o[k][enc["input_ids"].shape[1]:],
skip_special_tokens=True)
i += batch_size
except torch.cuda.OutOfMemoryError:
torch.cuda.empty_cache()
if batch_size == 1:
log(" OOM at batch=1; skipping this item")
i += 1
else:
batch_size = max(1, batch_size // 2)
log(f" OOM -> batch_size={batch_size}")
except Exception as e: # never die mid-run
log(f" generate error: {type(e).__name__}: {e}")
i += batch_size
return out
def solve_matching(row, n):
"""Score every (item, option) pair and take the best one-to-one assignment.
Free-form generation fails badly here: measured on the benchmark the
model just emits the option labels in order (A, B, C, ... == the
identity permutation), which is a *valid* permutation so no repair
fires, and it scores ~0. Asking for one letter at a time and reading
the next-token distribution turns the task into an assignment problem
the model is actually good at, and the one-to-one constraint is then
enforced exactly rather than hoped for.
"""
items, opts = parse_matching_block(row.get("context", ""))
if len(items) < 3 or len(opts) < 3 or len(items) != n:
return None
letters = [o[0] for o in opts]
# token id for each option letter, bare and space-prefixed
cand_ids = []
for L in letters:
ids = set()
for form in (L, " " + L):
t = tok.encode(form, add_special_tokens=False)
if t:
ids.add(t[0])
cand_ids.append(sorted(ids))
ctx = row["context"].strip()
prompts_m = []
for num, itext in items:
msgs = [
{"role": "system", "content":
"You match items to their correct counterparts in a "
"linguistics problem. Reply with one option letter only."},
{"role": "user", "content":
f"{ctx}\n\nWhich lettered option corresponds to item {num} "
f"({itext})? Reply with the option letter only."},
]
prompts_m.append(tok.apply_chat_template(
msgs, tokenize=False, add_generation_prompt=True))
score = []
bs = 4
for s0 in range(0, len(prompts_m), bs):
if left() < 30:
return None
chunk = prompts_m[s0:s0 + bs]
enc = tok(chunk, return_tensors="pt", padding=True,
truncation=True, max_length=6144).to(model.device)
with torch.no_grad():
logits = model(**enc).logits[:, -1, :].float()
logprobs = torch.log_softmax(logits, dim=-1)
for b in range(len(chunk)):
score.append([max(logprobs[b, i].item() for i in ids)
for ids in cand_ids])
col = best_assignment(score)
return [letters[c] for c in col]
# --- 3. Pass 1: greedy, guarantees a full answer set --------------------
# Size the reasoning budget to the actual problem count. Measured on the
# eval hardware (T4, 14B AWQ, batch 4) throughput is ~32 tok/s, so the whole
# 30 minutes buys only ~50k generated tokens. With ~16 problem blocks that
# affords full-length reasoning; if the platform instead ships one row per
# sub-question (~90 rows) a fixed 900-token budget would not even finish a
# single pass. Spend at most ~40% of what's left on pass 1.
TOK_PER_S = float(os.environ.get("IOL_TOKS", "30"))
adaptive = int(0.40 * max(1.0, left()) * TOK_PER_S / max(1, len(df)))
max_new = max(192, min(MAX_NEW, adaptive))
log(f"reasoning budget: {max_new} new tokens/problem "
f"(adaptive={adaptive}, cap={MAX_NEW}, {len(df)} problems)")
t = time.time()
texts = generate(prompts, max_new=max_new, sample=False)
pass1_cost = time.time() - t
samples = {i: [] for i in ids}
n_matched = 0
for (i, n, txt), (_, row) in zip(zip(ids, ns, texts), df.iterrows()):
if BASELINE_MODE:
# literally the organizers' parse: every non-empty stripped line,
# however many there are. No cleaning, no fallback, no forcing.
preds[i] = [ln.strip() for ln in (txt or "").splitlines() if ln.strip()]
samples[i].append(preds[i])
continue
a = repair_bijection(parse_answers(txt, n, srcs[i]))
# match_letters: free-form generation emits the identity permutation
# (A, B, C, ...) and scores ~0, so solve it as an assignment instead.
if (row.get("task_type") or "").strip().lower() == "match_letters":
try:
mm_ = solve_matching(row, n)
if mm_ and len(mm_) == n:
a = mm_
n_matched += 1
except Exception as e:
log(f" matching solver failed on {i}: {type(e).__name__}: {e}")
preds[i] = a
samples[i].append(a)
if n_matched:
log(f"assignment solver used on {n_matched} match_letters problem(s)")
write_submission(OUT_CSV, ids, preds, explanations)
# How often did reasoning run past the token budget before the model got to
# its ANSWERS: block? Those problems fall back to salvaged lines, so a high
# count means max_new is too small rather than the model being wrong.
no_block = sum(1 for txt in texts
if not re.search(r"answers?\s*:", txt or "", re.I))
empty = sum(1 for txt in texts if not (txt or "").strip())
log(f"pass 1 (greedy) done in {pass1_cost:.0f}s -> submission written "
f"({no_block}/{len(texts)} without an ANSWERS: block, {empty} empty)")
dev_score(preds)
# --- 4. Self-consistency passes while budget allows ---------------------
reserve = 0.0
if WANT_EXPLANATION:
reserve = min(300.0, 0.25 * pass1_cost + 60) # explanations are short
n_extra = 0
while (not BASELINE_MODE and left() - reserve > pass1_cost * 1.25 and n_extra < MAX_SAMPLES):
n_extra += 1
log(f"self-consistency pass {n_extra} ({left():.0f}s left)")
texts = generate(prompts, max_new=max_new, sample=True, temp=SAMPLE_TEMP)
for i, n, txt in zip(ids, ns, texts):
if txt:
samples[i].append(repair_bijection(parse_answers(txt, n, srcs[i])))
for i, n in zip(ids, ns):
if len(samples[i]) >= 2: # was >= 3
greedy = samples[i][0]
preds[i] = repair_bijection(
[vote([s[k] for s in samples[i] if k < len(s)],
anchor=greedy[k] if k < len(greedy) else None)
for k in range(n)])
write_submission(OUT_CSV, ids, preds, explanations)
log(f" voted over {n_extra + 1} samples (greedy-anchored) -> written")
dev_score(preds)
# --- 5. Explanations for the jury track ---------------------------------
if WANT_EXPLANATION and left() > 60:
log(f"generating explanations ({left():.0f}s left)")
ex_prompts = []
for (_, r), i in zip(df.iterrows(), ids):
msgs = [{"role": "system", "content": EXPLAIN_SYSTEM},
{"role": "user", "content": build_explain_prompt(r, preds[i])}]
ex_prompts.append(tok.apply_chat_template(
msgs, tokenize=False, add_generation_prompt=True))
ex = generate(ex_prompts, max_new=200, sample=False)
for i, e in zip(ids, ex):
e = re.sub(r"\s+", " ", (e or "").strip())
if e:
explanations[i] = e[:1200]
write_submission(OUT_CSV, ids, preds, explanations)
log("explanations written")
# --- 6. Final integrity check ------------------------------------------
bad = [i for i, n in zip(ids, ns) if len(preds[i]) != n or any(
not str(x).strip() for x in preds[i])]
if bad:
log(f"repairing {len(bad)} malformed rows")
for i, n in zip(ids, ns):
preds[i] = fit_to_n([x for x in preds[i] if str(x).strip()], n, srcs[i])
write_submission(OUT_CSV, ids, preds, explanations)
log(f"DONE. {len(ids)} rows, {sum(len(v) for v in preds.values())} answers, "
f"{time.time() - T0:.0f}s elapsed")
if __name__ == "__main__":
main()