結果

問題 No.917 Make One With GCD
ユーザー lam6er
提出日時 2025-03-20 18:56:52
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 156 ms / 2,000 ms
コード長 1,900 bytes
コンパイル時間 209 ms
コンパイル使用メモリ 82,572 KB
実行使用メモリ 77,812 KB
最終ジャッジ日時 2025-03-20 18:58:15
合計ジャッジ時間 3,111 ms
ジャッジサーバーID
(参考情報)
judge5 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 4
other AC * 32
権限があれば一括ダウンロードができます

ソースコード

diff #

def factorize(x):
    factors = {}
    if x == 1:
        return factors
    i = 2
    while i * i <= x:
        while x % i == 0:
            factors[i] = factors.get(i, 0) + 1
            x = x // i
        i += 1
    if x > 1:
        factors[x] = 1
    return factors

def generate_divisors(factors):
    if not factors:
        return [(1, 1)]
    primes = list(factors.keys())
    exponents = [factors[p] for p in primes]
    divisors = []
    current_exponents = [0] * len(primes)
    
    def backtrack(index):
        if index == len(primes):
            d = 1
            has_square = False
            prime_count = 0
            for i in range(len(primes)):
                p = primes[i]
                e = current_exponents[i]
                d *= p ** e
                if e >= 2:
                    has_square = True
                if e >= 1:
                    prime_count += 1
            mu = 0 if has_square else (-1) ** prime_count
            divisors.append((d, mu))
            return
        for e in range(0, exponents[index] + 1):
            current_exponents[index] = e
            backtrack(index + 1)
    
    backtrack(0)
    return divisors

def main():
    import sys
    input = sys.stdin.read().split()
    N = int(input[0])
    A = list(map(int, input[1:N+1]))
    
    divisors_dict = {}
    for x in A:
        factors = factorize(x)
        generated = generate_divisors(factors)
        for d, mu in generated:
            if d not in divisors_dict:
                divisors_dict[d] = mu
    
    sum_ans = 0
    for d in divisors_dict:
        mu = divisors_dict[d]
        if mu == 0:
            continue
        cnt = 0
        for a in A:
            if a % d == 0:
                cnt += 1
        if cnt == 0:
            continue
        term = mu * ((1 << cnt) - 1)
        sum_ans += term
    print(sum_ans)

if __name__ == "__main__":
    main()
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