"""# ### 谜题描述 Now you get Baby Ehab's first words: \"Given an integer n, find the longest subsequence of [1,2, …, n-1] whose product is 1 modulo n.\" Please solve the problem. A sequence b is a subsequence of an array a if b can be obtained from a by deleting some (possibly all) elements. The product of an empty subsequence is equal to 1. Input The only line contains the integer n (2 ≤ n ≤ 10^5). Output The first line should contain a single integer, the length of the longest subsequence. The second line should contain the elements of the subsequence, in increasing order. If there are multiple solutions, you can print any. Examples Input 5 Output 3 1 2 3 Input 8 Output 4 1 3 5 7 Note In the first example, the product of the elements is 6 which is congruent to 1 modulo 5. The only longer subsequence is [1,2,3,4]. Its product is 24 which is congruent to 4 modulo 5. Hence, the answer is [1,2,3]. Here is a reference code to solve this task. You can use this to help you genereate cases or validate the solution. ```python #!/usr/bin/env python # https://github.com/cheran-senthil/PyRival from __future__ import division, print_function import os import sys from io import BytesIO, IOBase from collections import defaultdict if sys.version_info[0] < 3: from __builtin__ import xrange as range from future_builtins import ascii, filter, hex, map, oct, zip def main(): import math def prime_factors(n): factors = [] while n % 2 == 0: factors.append(2) n //= 2 for i in range(3, int(math.sqrt(n)) + 1, 2): while n % i == 0: factors.append(i) n //= i if n > 2: factors.append(n) return factors N = int(input()) s = [True] * N for p in set(prime_factors(N)): for k in range(p, N, p): s[k] = False p = 1 ans = [] for j in range(1, N): if s[j]: p = (p * j) % N ans.append(j) if p != 1: ans.remove(p) print(len(ans)) print(' '.join(map(str, ans))) # region fastio BUFSIZE = 8192 class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = \"x\" in file.mode or \"r\" not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b\"\n\") + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode(\"ascii\")) self.read = lambda: self.buffer.read().decode(\"ascii\") self.readline = lambda: self.buffer.readline().decode(\"ascii\") def print(*args, **kwargs): \"\"\"Prints the values to a stream, or to sys.stdout by default.\"\"\" sep, file = kwargs.pop(\"sep\", \" \"), kwargs.pop(\"file\", sys.stdout) at_start = True for x in args: if not at_start: file.write(sep) file.write(str(x)) at_start = False file.write(kwargs.pop(\"end\", \"\n\")) if kwargs.pop(\"flush\", False): file.flush() if sys.version_info[0] < 3: sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout) else: sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) input = lambda: sys.stdin.readline().rstrip(\"\r\n\") # endregion if __name__ == \"__main__\": main() ``` 请完成上述谜题的训练场环境类实现,包括所有必要的方法。 """ from bootcamp import Basebootcamp import math import random from bootcamp import Basebootcamp class Cproduct1modulonbootcamp(Basebootcamp): def __init__(self, min_n=2, max_n=10**5): self.min_n = max(2, min_n) self.max_n = min(10**5, max_n) def case_generator(self): # 基础随机生成(80%概率) if random.random() < 0.8: n = random.randint(self.min_n, self.max_n) else: # 特殊案例生成(20%概率) candidates = self._generate_special_candidates() n = random.choice(candidates) if candidates else random.randint(self.min_n, self.max_n) return {'n': n} def _generate_special_candidates(self): candidates = [] # 质数列表(动态生成范围内) primes = [p for p in [2,3,5,7,11,13,17,19,23,29] if self.min_n <= p <= self.max_n] if primes: candidates.append(random.choice(primes)) # 平方数生成 max_square_root = int(math.sqrt(self.max_n)) squares = [x*x for x in range(2, max_square_root+1) if x*x >= self.min_n] if squares: candidates.append(random.choice(squares)) # 合数生成(至少两个不同质因数) composites = [] for x in range(max(4, self.min_n), min(100, self.max_n)+1): factors = set() num = x for i in [2,3,5,7]: if num % i == 0: factors.add(i) while num % i == 0: num //= i if num > 1: factors.add(num) if len(factors) >= 2: composites.append(x) if composites: candidates.append(random.choice(composites)) return candidates if candidates else [random.randint(self.min_n, self.max_n)] @staticmethod def prompt_func(question_case): n = question_case['n'] return f"""Given integer n={n}, find the longest increasing subsequence of [1,2,...,{n-1}] where the product ≡1 mod n. Output format: [answer] [/answer]""" @staticmethod def extract_output(output): import re matches = re.findall(r'\[answer\](.*?)\[/answer\]', output, re.DOTALL) if not matches: return None last_match = matches[-1].strip() lines = [line.strip() for line in last_match.split('\n') if line.strip()] if len(lines) < 2: return None try: length = int(lines[0]) elements = list(map(int, lines[1].split())) if len(elements) != length or elements != sorted(elements): return None return elements except: return None @classmethod def _verify_correction(cls, solution, identity): n = identity['n'] # 基础校验 if not solution or len(solution) == 0: return False if any(e < 1 or e >= n for e in solution): return False if solution != sorted(solution) or len(solution) != len(set(solution)): return False # 互质验证 prime_factors = set() num = n for p in [2,3,5,7,11,13,17,19]: if num % p == 0: prime_factors.add(p) while num % p == 0: num //= p if num > 1: prime_factors.add(num) for e in solution: if any(e % p == 0 for p in prime_factors): return False # 乘积验证 product = 1 for x in solution: product = (product * x) % n return product == 1 and len(solution) == cls._calculate_expected_length(n) @classmethod def _calculate_expected_length(cls, n): # 计算理论最大长度 coprimes = [x for x in range(1, n) if math.gcd(x, n) == 1] product = 1 for x in coprimes: product = (product * x) % n return len(coprimes) - (0 if product == 1 else 1)