Problem:


Score : 100 points

Problem Statement

Given is an integer N.

Takahashi chooses an integer a from the positive integers not greater than N with equal probability.

Find the probability that a is odd.

Constraints

1 \leq N \leq 100

Input

Input is given from Standard Input in the following format:

N

Output

Print the probability that a is odd.
Your output will be considered correct when its absolute or relative error from the judge's output is at most 10^{-6}.

Sample Input 1

4

Sample Output 1

0.5000000000

There are four positive integers not greater than 4: 1, 2, 3, and 4. Among them, we have two odd numbers: 1 and 3. Thus, the answer is \frac{2}{4} = 0.5.

Sample Input 2

5

Sample Output 2

0.6000000000

Sample Input 3

1

Sample Output 3

1.0000000000



Sample input:
4


Sample output:
0.5000000000

Submission status: Accepted

Solution code:
import math

def main():
    N = int(input())

    print(math.ceil(N/2) / N)



if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
num = int(input())

count = 0
for i in range(num):
    if i % 2 == 0:
        count = count + 1

print(count / num)

Submission status: Accepted

Solution code:
n = int(input())

print((int(n/2)+n%2)/n)

Submission status: Accepted

Solution code:
import sys
sys.setrecursionlimit(100000)

def ins(): return input().split()
def ii(): return int(input())
def iil(): return list(map(int,ins()))
def lin(): return list(input())
def iin(): return map(int,ins())

a = ii()
print(((a+1)//2)/a)

Submission status: Accepted

Solution code:
a = int(input())

if a%2==0:
    print(0.5)
elif a==1:
    print(1.0)
else:
    print((a//2+1)/a)

Submission status: Accepted

Solution code:
N = int(input())

i = 1
count = 0
while i <= N:
  if i % 2 ==0:
    i+=1
  else:
    count += 1
    i += 1
    
print(count/N)

Submission status: Accepted

Solution code:
def answer():
    n = int(input())
    c = n//2
    b = n - c
    print(b/n)


if __name__ == '__main__':
    answer()

Submission status: Accepted

Solution code:
N=int(input())

if N%2==0:
    print(0.5)
else:
    print(1-(N//2)/N)

Submission status: Accepted

Solution code:
A = int(input())

ans = 0

odd = 0
even = 0

for n in range(A, 0, -1):
    # print(n)
    if n % 2 == 0:
        even += 1
    else:
        odd += 1

print(odd/(even+odd))

Submission status: Accepted

Solution code:
import sys

input = sys.stdin.readline


class AtCoder:
    def main(self):
        N = int(input())

        if N % 2 == 0:
            print(1 / 2)
        else:
            print((N // 2 + 1) / N)


# Run main
if __name__ == '__main__':
    AtCoder().main()

Submission status: Accepted

Solution code:
N = int(input())

if N == 1:
    print(1)
else:
    if N % 2 == 0:
        print(0.5)
    else:
        print((N // 2 + 1) / N)

Submission status: Accepted

Solution code:
N = int(input())
cnt = 0
for i in range(1, N + 1):
    if i % 2 != 0:
        cnt += 1

print(cnt / N)

Submission status: Accepted

Solution code:
n = int(input())

if n%2==0:
    print(0.5)
else:
    print((n//2+1)/n)

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
import sys


def solve(N: int):
    count = 0
    for i in range(1, N+1):
        if i  % 2 != 0:
            count += 1
    print(count / N)
    return


# Generated by 1.1.5 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    solve(N)

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
import sys
input = sys.stdin.readline

def main():
    n = int(input())
    ans = n // 2
    ans = ans / n
    print(1-ans)

if __name__ == '__main__': main()

Submission status: Accepted

Solution code:
n = int(input())
u = n//2+n%2
print(u/n)

Submission status: Accepted

Solution code:
n = int(input())

if n % 2 == 0:
    print((n//2)/n)
else:
    print((n//2+1)/n)

Submission status: Accepted

Solution code:
N = int(input())
print(1 - int(N/2)/N)

Submission status: Accepted

Solution code:
n = int(input())

if n == 1:
  print("1")

elif n%2 == 0:
  print("0.500000000")

else:
  print((n//2+1)/n)

Submission status: Accepted

Solution code:
N=int(input())
s = 0
for i in range(1, N+1):
  if i % 2 != 0:
    s += 1
res = s / N
print(res)

Submission status: Accepted

Solution code:
n = int(input())

if n % 2 == 0:
    print(1/2)
else:
    res = ((n // 2) + 1) / n
    print(res)

Submission status: Accepted

Solution code:
#A

n = int(input())

ki = (n+1) // 2

guu = n // 2

ans = ki / n

print(ans)

Submission status: Accepted

Solution code:
n = int(input())
k = n//2
z = n-k
 
print(z/n)

Submission status: Accepted

Solution code:
N = int(input())
if N % 2 == 0:
    print(int((N/2))/N)
else:
    print((int((N/2))+1)/N)

Submission status: Accepted

Solution code:
N = int(input())

if N % 2 ==1:
    print((N//2 + 1) / float(N))
else:
    print(1.0/2)

Submission status: Accepted

Solution code:
N = int(input())

ans = 0.5
if N % 2 == 1:
  ans = (N // 2 + 1) / N

print(ans)

Submission status: Accepted

Solution code:
a = int(input())
g = 0
k = 0
for i in range(1,a+1):
    if i %2== 1:
        k +=1
    else:
        g+=1


print(k/a)

Submission status: Accepted

Solution code:
from math import ceil

N = int(input())
num_odds = ceil(N / 2)
print(num_odds / N)

Submission status: Accepted

Solution code:
n = int(input())
if n % 2 == 0:
    print(0.5)
else:
    print(((n-1)/2 + 1) / n)

Submission status: Accepted

Solution code:
N = int(input().strip())
if N % 2 == 0:
    print(0.5)
else:
    print((N//2 + 1)/ N)

Submission status: Accepted

Solution code:
N = int(input())
if N%2 == 0:
    print(0.5)
else:
    print((N//2 + 1)/N)

Submission status: Accepted

Solution code:
# coding: utf-8

import sys
import math
import collections
import itertools
from inspect import currentframe
INF = 10 ** 10
MOD = 10 ** 9 + 7
def input() : return sys.stdin.readline().strip()
def gcd(x, y) : return y if x % y == 0 else gcd(y, x % y)
def lcm(x, y) : return (x * y) // gcd(x, y)
def I() : return int(input())
def MI() : return map(int, input().split())
def LI() : return [int(x) for x in input().split()]
def RI(N) : return [int(input()) for _ in range(N)]
def LRI(N) : return [[int(x) for x in input().split()] for _ in range(N)]
def chkprint(*args) : names = {id(v):k for k,v in currentframe().f_back.f_locals.items()}; print(', '.join(names.get(id(arg),'???')+' = '+repr(arg) for arg in args))

N = I()

print(math.ceil(N / 2) / N)

Submission status: Accepted

Solution code:
N=int(input())
A=list(range(1,N+1))
B=list(range(1,N+1,2))
print(len(B)/len(A))

Submission status: Accepted

Solution code:
#!/usr/bin/env python3


def solve(N):
    if N % 2 == 0:
        return 0.5
    else:
        return (N // 2 + 1) / N


if __name__ == '__main__':
    N = int(input())

    ans = solve(N)

    print(ans)

Submission status: Accepted

Solution code:
n = int(input())

kisuu = 0
for i in range(1, n+1):
    if i%2 == 1:
        kisuu += 1

print(kisuu / n)

Submission status: Accepted

Solution code:
N = int(input())

odd = 0
even = 0
for n in range(1, N+1):
    if n % 2 == 0:
        even += 1
    else:
        odd += 1
print(odd/(odd+even))

Submission status: Accepted

Solution code:
n = int(input())

if n%2 == 0:
    print(1/2)
elif n == 1:
    print(1)
else:
    print(((n+1)/2)/n)

Submission status: Accepted

Solution code:
n=int(input())

cn=0
for i in range(1,n+1):
    if i%2==1:
        cn+=1

print(cn/n)

Submission status: Accepted

Solution code:
#[int(i) for i in input().split()]
n = int(input())
if n % 2 == 0:
    print(1/2)
else:
    print(((n+1)/2)/n)

Submission status: Accepted

Solution code:
#!/usr/bin/env python

import sys

n= int(sys.stdin.readline())
o= n - n//2

print( float( o ) / n )

Submission status: Accepted

Solution code:
n=int(input())
kisu=n-n//2
print(kisu/n)

Submission status: Accepted

Solution code:
n = int(input())

if n%2 ==0:
    print(0.5)
else:
    print((n//2+1)/n)

Submission status: Accepted

Solution code:
n = int(input())

answer = 0

if n % 2 == 0:
    answer = 0.5
else:
    answer = ((n // 2) + 1) / n

print(answer)

Submission status: Accepted

Solution code:
n = int(input())
p = (n+1)//2
print(p/n)

Submission status: Accepted

Solution code:
N = int(input())
if N%2 == 0:
    print(0.50)
else:
    odd = (N//2) +1
    print(odd/N)

Submission status: Accepted

Solution code:
n = int(input())
j = 0
for i in range(1,n+1):
    if i % 2 == 1:
        j += 1
        
print(j/n)

Submission status: Accepted

Solution code:
from sys import stdin

def main():
    input = lambda: stdin.readline()[:-1]
    N = int(input())

    odd = 0
    for i in range(N, 0, -1):
        odd += i % 2
    print(odd / N)

main()

Submission status: Accepted

Solution code:
n = int(input())
if n%2 == 0:
    print(1/2)
else:
    print((n//2 + 1)/n)

Submission status: Accepted

Solution code:
def read():
    N = int(input().strip())
    return N

def solve(N):
    even = N // 2
    odds = N - even
    return 1.0 * odds / N

if __name__ == '__main__':
    inputs = read()
    print("%.8f" % solve(inputs))

Submission status: Accepted

Solution code:
N = int(input())

print(1 - (N//2) / N)

Submission status: Accepted

Solution code:
# A
# int(input().split
N = int(input())

cnt = 0
for i in range(1,N+1):
    if (i % 2 != 0):
        cnt += 1
print(cnt / N)

Submission status: Accepted

Solution code:
N = int(input())

ki = N // 2 + N % 2

print(ki / N)

Submission status: Accepted

Solution code:
import math
n = int(input())
ans = math.ceil(n / 2) / n
print(ans)

Submission status: Accepted

Solution code:
import sys
input=sys.stdin.readline

def main():
    N = int(input())
    print(((N+1)//2)/N)

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
N=input()
if N%2==0:
	print float(N/2)/N
else:
	print float(N/2+1)/N

Submission status: Accepted

Solution code:
N = int(input())
a = N // 2
if N % 2 == 0:
    print(1/2)
else:
    a += 1
    prob = a/N
    print(prob)

Submission status: Accepted

Solution code:
import sys

stdin = sys.stdin

ns = lambda : stdin.readline().rstrip()
ni = lambda : int(ns())
na = lambda : map(int, stdin.readline().split())

def main():
  n = ni()

  odd = 1 if n%2 == 1 else 0
  for i in range(1, n+1):
    if i%2 == 0:
      odd += 1
  print(odd/n)

main()

Submission status: Accepted

Solution code:
N = int(input())

if N%2==0:
    print(N//2/N)
else:
    print((N//2+1)/N)

Submission status: Accepted

Solution code:
n = int(input())

cnt = 0
for i in range(1, n+1):
    cnt += i % 2 == 1

print(cnt / n)

Submission status: Accepted

Solution code:
n = int(input())
if n%2 == 0:
  print(0.5)
else:
  print((n+1)/(2*n))

Submission status: Accepted

Solution code:
n = int(input())

if n%2==0:
    print(0.5)
else:
    a = (n+1)//2
    print(a/n)

Submission status: Accepted

Solution code:
n = int(input())
total = 0
for i in range(1, n+1):
    if i % 2 == 1:
        total += 1
print(total/n)

Submission status: Accepted

Solution code:
N = int(input())

a = ((N+1)/2)/N if N%2 == 1 else 0.5
print(a)

Submission status: Accepted

Solution code:
n = int(input())

if n == 1:
  print(1)
elif n%2==0:
  print(0.5)
else:
  print((n+1)/2/n)

Submission status: Accepted

Solution code:
n = int(input())

count = 0
for i in range(n+1):
  if (i % 2) == 1:
    count += 1
print(count/n)

Submission status: Accepted

Solution code:
# coding: utf-8

n = int(input())
ans = 0
for i in range(1, n + 1):
    if i % 2 == 1:
        ans += 1


print(ans/n)

Submission status: Accepted

Solution code:
n = int(input())
m = 0
for i in range(n+1):
  if i % 2 == 1 :
    m+= 1

print(m/n)

Submission status: Accepted

Solution code:
n = int(input())

if n % 2 == 0:
    print(1 / 2)
else:
    print((n // 2 + 1) / n)

Submission status: Accepted

Solution code:
N = int(input())

if N % 2 == 0:
	print("0.5000000000")
else:
	print((N // 2 + 1) / N)

Submission status: Accepted

Solution code:
#coding:utf-8
n = int(input())

if n % 2 == 0:
    print((n/2)/n)
else:
    print((1 + (n//2))/n)

Submission status: Accepted

Solution code:
n = int(input())
if n%2==0:
  print(0.5)
else:
  print((n+1)/(2*n))

Submission status: Accepted

Solution code:
n=int(input())

if n%2==0:
  print(0.5)
else:
  print((n+1)/(2*n))

Submission status: Accepted

Solution code:
n = int(input())
if n % 2 == 0:
    print(1/2)
else:
    a = (n + 1)//2
    print(a/n)

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-                                                         
# 整数の入力                                                                    
a = int(input())
odd = (a // 2) + (a % 2)

print(odd / a)

Submission status: Accepted

Solution code:
n = int(input())

if n % 2 == 0:
    print(1/2)
else: 
    print((n//2+1)/n)

Submission status: Accepted

Solution code:
N = int(input())

count = 0
for i in range(1, N + 1):
    if i % 2 == 1:
        count += 1

print(count/N)

Submission status: Accepted

Solution code:
n = int(input())
if(n%2 == 0):
  print(0.5000000)
else:
  print((n//2 + 1)/n)

Submission status: Accepted

Solution code:
n=int(input())
odd = 0
evn = 0
for i in range(1,n+1):
    if i%2==1:
        odd+=1
        
print(odd/n)

Submission status: Accepted

Solution code:
def getlist():
	return list(map(int, input().split()))

N = int(input())
if N % 2 == 0:
	print(0.5)
else:
	print((N - (N // 2)) / N)

Submission status: Accepted

Solution code:
n=int(input())
nn=(n+1)//2
print(float(nn/n))

Submission status: Accepted

Solution code:
#!/usr/bin/env python
# coding: utf-8

def ri():
    return int(input())

def rl():
    return list(input().split())

def rli():
    return list(map(int, input().split()))

def main():
    n = ri()
    print((n%2 + n // 2) / n)


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
n = int(input())
if n%2 == 0:
    ans = (n/2)/n
else:
    ans = ((n+1)/2)/n
print(ans)

Submission status: Accepted

Solution code:
n=int(input())
if n%2 == 0:
    print(0.5)
else:
    print((int(n/2)+1)/n)

Submission status: Accepted

Solution code:
n = int(input())
li = []
for i in range(1,n+1):
    if i%2 != 0:
        li.append(i)
print(len(li)/n)

Submission status: Accepted

Solution code:
N = int(input())
print((N//2)/N if N%2 == 0 else ((N+1)//2)/N)

Submission status: Accepted

Solution code:
N=int(input())
if N%2==0:
    print(1/2)
else:
    print((N//2+1)/N)

Submission status: Accepted

Solution code:
n = int(input())
if n % 2 == 0:
    print(0.5)
else:
    print(((n // 2) + 1.0) / n)

Submission status: Accepted

Solution code:
N = int(raw_input())
num_odd = N/2 + N%2

print 1.0*num_odd/N

Submission status: Accepted

Solution code:
N = float(input())

if N % 2 == 0:
  P = 0.50
else:
  P = (N//2+1) / N
print (P)

Submission status: Accepted

Solution code:
N = int(input())
print(1 - (N//2)/N)

Submission status: Accepted

Solution code:
n = int(input())
odd = 0
for i in range(n):
    if (i + 1) % 2:
        odd += 1
print(odd / n)

Submission status: Accepted

Solution code:
def main(sample_file = ''):

    """ convenient functions
    # for i, a in enumerate(iterable)
    # q, mod = divmod(a, b)
    # divmod(x, y) returns the tuple (x//y, x%y)
    # Higher-order function: reduce(operator.mul, xyz_count, 1)
    # manage median(s) using two heapq https://atcoder.jp/contests/abc127/tasks/abc127_f
    """

    """convenient decorator
    # @functools.lru_cache():
    # to facilitate use of recursive function
        # ex:
        # from functools import lru_cache
        # import sys
        # sys.setrecursionlimit(10**9)
        # @lru_cache(maxsize=None)
        # def fib(n):
        #     if n < 2:
        #         return n
        #     return fib(n-1) + fib(n-2)
        # print(fib(1000))
    """
    
    # import numpy as np
    import sys
    sys.setrecursionlimit(10**7)
    from itertools import accumulate, combinations, permutations, product # https://docs.python.org/ja/3/library/itertools.html
    # accumulate() returns iterator! to get list: list(accumulate())
    from math import factorial, ceil, floor, sqrt
    def factorize(n):
        """return the factors of the Arg and count of each factor
        
        Args:
            n (long): number to be resolved into factors
        
        Returns:
            list of tuples: factorize(220) returns [(2, 2), (5, 1), (11, 1)]
        """
        fct = []  # prime factor
        b, e = 2, 0  # base, exponent
        while b * b <= n:
            while n % b == 0:
                n = n // b
                e = e + 1
            if e > 0:
                fct.append((b, e))
            b, e = b + 1, 0
        if n > 1:
            fct.append((n, 1))
        return fct
    def combinations_count(n, r):
        """Return the number of selecting r pieces of items from n kinds of items.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        # TODO: How should I do when n - r is negative?
        if n < 0 or r < 0:
            raise Exception('combinations_count(n, r) not defined when n or r is negative')
        if n - r < r: r = n - r
        if r < 0: return 0
        if r == 0: return 1
        if r == 1: return n
        numerator = [n - r + k + 1 for k in range(r)]
        denominator = [k + 1 for k in range(r)]
        for p in range(2,r+1):
            pivot = denominator[p - 1]
            if pivot > 1:
                offset = (n - r) % p
                for k in range(p-1,r,p):
                    numerator[k - offset] /= pivot
                    denominator[k] /= pivot
        result = 1
        for k in range(r):
            if numerator[k] > 1:
                result *= int(numerator[k])
        return result
    def combinations_with_replacement_count(n, r):
        """Return the number of selecting r pieces of items from n kinds of items allowing individual elements to be repeated more than once.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        if n < 0 or r < 0:
            raise Exception('combinations_with_replacement_count(n, r) not defined when n or r is negative')
        elif n == 0:
            return 1
        else:
            return combinations_count(n + r - 1, r)
    from bisect import bisect_left, bisect_right
    from collections import deque, Counter, defaultdict # https://docs.python.org/ja/3/library/collections.html#collections.deque
    from heapq import heapify, heappop, heappush, heappushpop, heapreplace,nlargest,nsmallest # https://docs.python.org/ja/3/library/heapq.html
    from copy import deepcopy, copy # https://docs.python.org/ja/3/library/copy.html
    import operator
    from operator import itemgetter #sort 
    # ex1: List.sort(key=itemgetter(1))
    # ex2: sorted(tuples, key=itemgetter(1,2))
    from functools import reduce, lru_cache
    def chmin(x, y):
        """change minimum
        if x > y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current minimum value
            y (long): potential minimum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x > y:
            x = y
            return (x, True)
        else:
            return (x, False)
    def chmax(x, y):
        """change maximum
        if x < y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current maximum value
            y (long): potential maximum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x < y:
            x = y
            return (x, True)
        else:
            return (x, False)

    from fractions import gcd # Deprecated since version 3.5: Use math.gcd() instead.
    def gcds(numbers):
        return reduce(gcd, numbers)
    def lcm(x, y):
        return (x * y) // gcd(x, y)
    def lcms(numbers):
        return reduce(lcm, numbers, 1)
    def make_divisors(n, reversed=False):
        """create list of divisors
        
        Args:
            number (int): number from which list of divisors is created
            reversed (bool, optional): ascending order if False. Defaults to False.
        
        Returns:
            list: list of divisors
        """
        divisors = set()
        for i in range(1, int(n**0.5)+1):
            if n % i == 0:
                divisors.add(i)
                divisors.add(n//i)
        return sorted(list(divisors),reverse=reversed)
    
    # first create factorial_list
    # fac_list = mod_factorial_list(n)
    INF = 10 ** 18
    MOD = 10 ** 9 + 7
    modpow = lambda a, n, p = MOD: pow(a, n, p) # Recursive function in python is slow!
    def modinv(a, p = MOD):
        # evaluate reciprocal using Fermat's little theorem:
        # a**(p-1) is identical to 1 (mod p) when a and p is coprime
        return modpow(a, p-2, p)
    def modinv_list(n, p = MOD):
        if n <= 1:
            return [0,1][:n+1]
        else:
            inv_t = [0,1]
            for i in range(2, n+1):
                inv_t += [inv_t[p % i] * (p - int(p / i)) % p]
            return inv_t
    def modfactorial_list(n, p = MOD):
        if n == 0:
            return [1]
        else:
            l = [0] * (n+1)
            tmp = 1
            for i in range(1, n+1):
                tmp = tmp * i % p
                l[i] = tmp
            return l
    def modcomb(n, k, fac_list = [], p = MOD):
        # fac_list = modfactorial_list(100)
        # print(modcomb(100, 5, modfactorial_list(100)))
        from math import factorial
        if n < 0 or k < 0 or n < k: return 0
        if n == 0 or k == 0: return 1
        if len(fac_list) <= n:
            a = factorial(n) % p
            b = factorial(k) % p
            c = factorial(n-k) % p
        else:
            a = fac_list[n]
            b = fac_list[k]
            c = fac_list[n-k]
        return (a * modpow(b, p-2, p) * modpow(c, p-2, p)) % p
    def modadd(a, b, p = MOD):
        return (a + b) % MOD
    def modsub(a, b, p = MOD):
        return (a - b) % p
    def modmul(a, b, p = MOD):
        return ((a % p) * (b % p)) % p
    def moddiv(a, b, p = MOD):
        return modmul(a, modpow(b, p-2, p))

    class UnionFindTree:
        """union find tree class
        TODO: fix this description...
        how to use (example):
        >>  uf = UnionFindTree(N) 
        >>  if uf.find_root(a) == uf.find_root(b):
        >>      do something
        >>  else:
        >>      do something
        >>      uf.unite(a, b)
        """
        def __init__(self, N):
            self.root = [-1] * (N+1)
            self.rank   = [0]  * (N+1)
            self.connected_num = [1] * (N+1)
    
        def find_root(self,x):
            root = self.root
            while root[x] != -1:
                x = root[x]
            return x
    
        def unite(self,x,y):
            root = self.root
            rank = self.rank
            connected_num = self.connected_num
            find_root = self.find_root
    
            rx = find_root(x)
            ry = find_root(y)
            if rx != ry:
                if rank[rx] < rank[ry]:
                    root[rx] = ry
                    rx,ry = ry,rx
                else:
                    if rank[rx] == rank[ry]:
                        rank[rx] += 1
                    root[ry] = rx       
                connected_num[rx] += connected_num[ry]

    # Graph: https://en.wikipedia.org/wiki/Directed_graph
    # Bellman-Ford: O(|V||E|). Use this if there exists an edge with negative length in the graph
    # After N steps, the shortest path has converded if there doesn't exist an cycle of edges with negative
    # Watch out: d[N] == d[2*N] doesn't necessarily mean the graph doesn't have negative cycle
    # ref: https://www.youtube.com/watch?v=1Z6ofKN03_Y

    def BellmanFord(N, M, ABC, vertex_start, vertex_end, value_if_inf = -1, find_shortest = False):
        """to calculate furthest or shortest length between vertex_start and vertex_end using BellmanFord algorithm
        
        Args:
            N (int): number of vertices
            M (int): number of edges
            ABC (list): [(ai, bi, ci) for _ in range(N)] where i-th edge is directed from vertex ai to vertex bi and the length is ci 
            vertex_start (int): start vertex. usually use 0.
            vertex_end (int): end vertex. usually use N-1.
            value_if_inf (int or string as you like, optional): value you want when the furthest (or shortest) distance is infinite (or -infinite). Defaults to -1.
            find_shortest (bool, optional): choose False to find furthest path. Defaults to False.
        
        Returns:
            int or string: normally int (but can be str if you set value_if_inf to str)
            
        Example:
                N, M, P = R()
                ABC = [R() for _ in range(M)]
                ABC = [(a-1, b-1, c-P) for a, b, c in ABC]
                print(BellmanFord(N, M, ABC, 0, N-1, value_if_inf = 'inf'))

        """

        def make_reachable_list(N, M, ABC, vertex_start, vertex_end):
            reachable_to_direct = defaultdict(list)
            reachable_from_direct = defaultdict(list)
            reachable_from_start = [False] * N
            reachable_to_end = [False] * N
            reachable_from_start[vertex_start] = True
            reachable_to_end[vertex_end] = True
            reachable_from_both_sides = [False] * N
            dfs_from_start = []
            dfs_to_end = []
            for a, b, c in ABC:
                reachable_to_direct[a].append(b)
                reachable_from_direct[b].append(a)
                if a == vertex_start:
                    dfs_from_start.append(b)
                    reachable_from_start[b] = True
                if b == vertex_end:
                    dfs_to_end.append(a)
                    reachable_to_end[a] = True
            while dfs_from_start:
                v = dfs_from_start.pop()
                for i in reachable_to_direct[v]:
                    if not reachable_from_start[i]:
                        reachable_from_start[i] = True
                        dfs_from_start.append(i)
            while dfs_to_end:
                v = dfs_to_end.pop()
                for i in reachable_from_direct[v]:
                    if not reachable_to_end[i]:
                        reachable_to_end[i] = True
                        dfs_to_end.append(i)
            for i in range(N):
                reachable_from_both_sides[i] = reachable_from_start[i] and reachable_to_end[i]
            return reachable_from_both_sides
        
        reachable_from_both_sides = make_reachable_list(N, M, ABC, vertex_start, vertex_end)
        
        if find_shortest:
            dist = [INF for i in range(N)]
        else:
            dist = [-INF for i in range(N)]
        
        dist[vertex_start] = 0
        for i in range(N):
            updated = False
            for a, b, c in ABC:
                if not reachable_from_both_sides[a]:
                    continue
                elif find_shortest:
                    update_condition = dist[a] + c < dist[b]
                else:
                    update_condition = dist[a] + c > dist[b]
                if dist[a] != INF and update_condition:
                    dist[b] = dist[a] + c
                    updated = True
                    if i == N-1:
                        return value_if_inf
            if not updated:
                break
        return dist[vertex_end]

    """ initialize variables and set inputs
    # initialize variables
        # to initialize list, use [0] * n
        # to initialize two dimentional array, use [[0] * N for _ in range(N)]
    # set inputs
        # put inputs between specific values (almost as quickly)
        # ex) S = [-INF] + [int(r()) for _ in range(A)] + [INF]
        # open(0).read() is sometimes useful:
        # ex) n, m, *x = map(int, open(0).read().split())
        #     min(x[::2]) - max(x[1::2])
        # ex2) *x, = map(int, open(0).read().split())
        #     don't forget to add comma after *x if only one variable is used
    # preprocessing
        # transpose = [x for x in zip(*data)]
        # ex) [[1, 2, 3], [4, 5, 6], [7, 8, 9]] => [(1, 4, 7), (2, 5, 8), (3, 6, 9)]
        # flat = [flatten for inner in data for flatten in inner]
        # ex) [[1, 2, 3], [4, 5, 6], [7, 8, 9]] => [1, 2, 3, 4, 5, 6, 7, 8, 9]
    # calculate and output
        # output pattern
        # ex1) print(*l) => when l = [2, 5, 6], printed 2 5 6
    """

    # functions to read input
    r = lambda: sys.stdin.readline().strip()
    r_int = lambda: int(r())
    R = lambda: list(map(int, r().split()))
    Rmap = lambda: map(int, r().split())
    Rfloat = lambda: list(map(float, r().split()))
    Rtuple = lambda: tuple(map(int, r().split()))

    """ how to treat input
    # single int: int(r())
    # single string: r()
    # single float: float(r())
    # line int: R()
    # line string: r().split()
    # line (str, int, int): [j if i == 0 else int(j) for i, j in enumerate(r().split())]
    # lines int: [R() for _ in range(n)]
    """

    # for test
    if sample_file:
        sys.stdin = open(sample_file)
        
    # ----------------------------------
    # main

    N = r_int()
    a = (1+N)//2
    print(a/N)
    

    # to finish code, use return instead of exit()
    # end of main
    # ----------------------------------

    """memo: how to use defaultdict of list
    # initialize
    Dic = defaultdict(list)
    # append / extend
    Dic[x].append(y)
    # three methods for loop: keys(), values(), items()
    for k, v in Dic.items():
    """
    
    """memo: how to solve binary problems
    # to make binary digits text
    >>> a = 5
    >>> bin_str_a = format(a, '#06b')
    >>> print(bin_str_a)
    0b0101 # first 2 strings (='0b') indicates it is binary
    """
    
    """memo: how to solve the problem
    creating simple test/answer
    greed
    simple dp
    graph
    """

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
if __name__ == '__main__':
    n = int(input())
    if n % 2 == 0:
        print(0.5)
    else:
        print((n//2+1)/n)

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
#ABC142 A

import sys
import math
from bisect import bisect_right as br
from bisect import bisect_left as bl
sys.setrecursionlimit(1000000000)
from heapq import heappush, heappop,heappushpop
from collections import defaultdict
from itertools import accumulate
from collections import Counter
from collections import deque
from operator import itemgetter
from itertools import permutations
mod = 10**9 + 7
inf = float('inf')
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))

n = I()
print(math.ceil(n/2)/n)

Submission status: Accepted

Solution code:

N = int(input())

count = 0

for i in range(N+1):
    if(i % 2 == 1):
        count += 1

print(count/N)

Submission status: Accepted

Solution code:
# coding: utf-8
# submission # - User: herp_sy
# https://atcoder.jp/contests/
#
# lang: Python3 (3.4.3)

import math
import statistics
import numpy as np

n = int(input())
print('{:.8f}'.format((n - n // 2) / n))