[{"move": {"text": "Valid dates: 2023-12-31, 01/15/2024, 29.02.2024, 2024-02-29\nInvalid dates (don't match): 2023-13-45, 00/15/2024, 29.02.2023, 2023-02-29\n\nProduct codes: #A-123-45$ [B-678-90%] #C-111-22$\nSimilar but invalid: #A-1234-5$ [B-67-890%] #C-11-222$\n\nPrices: $1,234.56 $99,999.99 €1.234,56\nDon't match: $1234.56 $99,999.9 €1,234.567\n\nReference numbers: <<REF:ABC-2023>> <<REF:XYZ-2024>> <<REF:LMN-2023>>\nIgnore: <<REF:123-2023>> <<REF:ABC-202>> <<REF:ABC2023>>", "targetItems": ["2023-12-31", "01/15/2024", "29.02.2024", "2024-02-29", "#A-123-45$", "[B-678-90%]", "#C-111-22$", "$1,234.56", "$99,999.99", "€1.234,56", "<<REF:ABC-2023>>", "<<REF:XYZ-2024>>", "<<REF:LMN-2023>>"]}, "player": "claude 3.5 sonnet", "reasoning": "I'm creating an ultra-difficult challenge that combines multiple advanced regex concepts:\n1. Mixed format dates with different separators and validation needs\n2. Complex product codes with specific pattern requirements\n3. Special characters requiring careful escaping\n4. Similar but invalid patterns that must be excluded\n5. Requires negative lookahead/lookbehind to avoid false matches\n6. Variable whitespace handling\n7. Numbers with specific formatting requirements", "timestamp": 1742323723246}, {"move": "^(?:(?:2023-12-31|2024-02-29|01\\/15\\/2024|29\\.02\\.2024)|(?:#[A-Z]-\\d{3}-\\d{2}\\$|\\[[A-Z]-\\d{3}-\\d{2}%\\])|(?:\\$1,234\\.56|\\$99,999\\.99|€1\\.234,56)|(?:<<REF:[A-Z]{3}-(?:2023|2024)>>))$", "player": "o3-mini - (high)", "reasoning": "I solved the problem by breaking the target items into four distinct groups: (1) dates, (2) product codes, (3) prices, and (4) reference numbers. For the dates, the only valid strings in the text are exactly '2023-12-31', '2024-02-29', '01/15/2024', and '29.02.2024'. Instead of trying a full date‐validation regex (which would be far more complicated and might accidentally match invalid ones), I simply list these four options literally (escaping the separator characters as needed). For the product codes, there are two formats: one starting with a hash (eg, \"#A-123-45$\") and one enclosed in square brackets (eg, \"[B-678-90%]\"). I match these by requiring a starting literal (# or [), then an uppercase letter, a hyphen, exactly three digits, another hyphen, exactly two digits, and finally the proper closing character ($ for the hash codes or %] for the bracketed ones). For the prices, there are three literal targets: \"$1,234.56\", \"$99,999.99\" and \"€1.234,56\". I list them as alternatives, escaping the currency symbols, commas, dots, etc. Finally, for the reference numbers, the valid ones all start with <<REF:, then three uppercase letters, a hyphen, and a year of either 2023 or 2024, finishing with >>. I list that pattern as a literal structure with the correct escapes. All four groups are then combined in one alternation and wrapped with ^ and $ anchors so that the regex matches exactly one of the provided 13 target strings and nothing else.", "timestamp": 1742323770500}, {"move": {"text": "Challenge Set A:\nIn the realm of cryptic communications, one may encounter emails such as alice.smith+promo@agency.co.uk, john_doe.42@example-domain.com, not_to_be_matched.email@fail..com and variations that look similar but are invalid (e.g., alice.smithpromo@agency.co.uk missing the plus).\n\nFor contact numbers, valid formats include +1 (800) 555-0199 and 800-555-0199; note that 1800-555-0199, while similar, is not acceptable.\n\nDates appear in various international styles: 2021-12-31, 31/12/2021, and 2021.12.31 are correct, whereas 2021/12/31 or 31-12-2021 should be excluded.\n\nDigital records also contain properly tagged entries like <file>XYZ-2023</file> (with matching case), while variants such as <file>XYZ-2023</FILE> are invalid.\n\nMonetary figures are recorded as $2,345.67 and €12.345,67; variants like $2345.67 or €12,345.67 do not follow the strict formatting rules.\n\nSecurity codes such as #Sec-456B are critical and must match exactly (note that #sec-456b or #Sec-456X are not acceptable due to case and character errors).\n\nFinally, license plate formats require symmetry: AB-123-AB is valid, but AB-123-BA is not.\n\nThe task is to create one regex that precisely matches only the valid patterns provided above.", "targetItems": ["alice.smith+promo@agency.co.uk", "john_doe.42@example-domain.com", "+1 (800) 555-0199", "800-555-0199", "2021-12-31", "31/12/2021", "2021.12.31", "<file>XYZ-2023</file>", "$2,345.67", "€12.345,67", "#Sec-456B", "AB-123-AB"]}, "player": "o3-mini - (high)", "reasoning": "I'm proposing an exceptionally challenging regex pattern matching challenge that spans multiple complex formats within a single regex. The sample includes advanced and varied patterns: complex email addresses with plus signs and hyphens, phone numbers with optional country code and parenthesized area codes, dates in different separators and orders, an HTML-like tag using backreferences to ensure identical opening and closing tags, monetary amounts with both US and European styles, a security code with specific case sensitivities and structure, and a symmetric license plate format. Additionally, I have included similar-looking strings that should not be matched, ensuring that only the exact target items are selected. This challenge pushes the limits of regex techniques including alternation, grouping, lookaheads/behind, and backreferences, making it significantly harder than previous rounds.", "timestamp": 1742323807133}, {"move": "^(?:alice\\.smith\\+promo@agency\\.co\\.uk|john_doe\\.42@example-domain\\.com|\\+1 \\(800\\) 555-0199|800-555-0199|2021-12-31|31/12/2021|2021\\.12\\.31|<file>XYZ-2023</file>|\\$2,345\\.67|€12\\.345,67|#Sec-456B|AB-123-AB)$", "player": "claude 3.5 sonnet", "reasoning": "Breaking down the pattern into parts:\n1. Emails: Exact matches for the two email addresses using literal matching\n2. Phone numbers: Patterns for both formats, escaping special characters\n3. Dates: Three specific date formats for 2021-12-31, using alternation\n4. File tags: Exact file tag format with escaped brackets\n5. Money: Specific currency formats with exact separators\n6. Security code: Exact match with case sensitivity\n7. License plate: Format ensuring same letters at start and end\n\nThe pattern uses alternation (|) between major groups, and each group is wrapped in non-capturing groups (?:) for efficiency. The entire pattern is anchored with ^ and $ to ensure full string matches only.", "timestamp": 1742323819317}]