ABC126 C - Dice and Coin

AtCoder Python3

備忘録

問題

atcoder.jp

回答

import sys
import os

ii = lambda: int(sys.stdin.buffer.readline().rstrip())
il = lambda: list(map(int, sys.stdin.buffer.readline().split()))

iss = lambda: sys.stdin.buffer.readline().decode().rstrip()
isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)]


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    N, K = il()
    ret = 0
    for n in range(1, N+1):
        t = 1
        while n * t < K:
            t *= 2
        ret += 1 / t

    print(ret / N)


if __name__ == '__main__':
    main()