結果

問題 No.1383 Numbers of Product
ユーザー gew1fw
提出日時 2025-06-12 20:33:06
言語 PyPy3
(7.3.15)
結果
MLE  
実行時間 -
コード長 2,219 bytes
コンパイル時間 253 ms
コンパイル使用メモリ 82,460 KB
実行使用メモリ 711,376 KB
最終ジャッジ日時 2025-06-12 20:34:08
合計ジャッジ時間 4,449 ms
ジャッジサーバーID
(参考情報)
judge3 / judge2
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 * 2
other AC * 5 MLE * 1 -- * 45
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 #

import sys
from collections import defaultdict

def main():
    N, K, M = map(int, sys.stdin.readline().split())
    count = defaultdict(int)
    max_B = 0

    B = 1
    while True:
        # Compute minimal product for B: A=1
        product_min = 1
        valid = True
        for i in range(B + 1):
            term = 1 + i * K
            if product_min > N // term:
                valid = False
                break
            product_min *= term
            if product_min > N:
                valid = False
                break
        if not valid:
            break

        # Binary search for A_max
        low = 1
        high = 1
        while True:
            product = 1
            for i in range(B + 1):
                term = high + i * K
                if term > N or product > N // term:
                    product = N + 1
                    break
                product *= term
            if product <= N:
                high *= 2
                if high > N:
                    high = N
                    break
            else:
                break

        a_max = 0
        while low <= high:
            mid = (low + high) // 2
            product = 1
            for i in range(B + 1):
                term = mid + i * K
                if term > N or product > N // term:
                    product = N + 1
                    break
                product *= term
            if product <= N:
                a_max = mid
                low = mid + 1
            else:
                high = mid - 1

        if a_max == 0:
            B += 1
            continue

        # Iterate A from 1 to a_max and compute X
        for A in range(1, a_max + 1):
            product = 1
            for i in range(B + 1):
                term = A + i * K
                if term > N or product > N // term:
                    product = N + 1
                    break
                product *= term
            if product <= N:
                count[product] += 1

        B += 1

    # Count the X's with exactly M occurrences
    result = 0
    for x in count:
        if x <= N and count[x] == M:
            result += 1
    print(result)

if __name__ == "__main__":
    main()
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