Submission #333789

#	Time	Username	Problem	Language	Result	Execution time	Memory
333789		limabeans	Odd-even (IZhO11_oddeven)	Cpython 3	0 / 100	30 ms	3948 KiB

oddeven

import sys
from math import *
from fractions import gcd
from random import * # randint(inclusive,inclusive)
readints=lambda:map(int, input().strip('\n').split())
from itertools import permutations, combinations
ALP = "abcdefghijklmnopqrstuvwxyz"
# print('', end=" ")
# for i in {1..5}; do echo "hi"; done

def randarr(n, lo, hi):
    assert(lo<=hi)
    return [randint(lo,hi) for _ in range(n)]


def randstr(n):
    s=''
    for _ in range(n):
        s += ALP[randint(0,25)]
    return s
    

def randtree(n):
    pass


##############################################################################


def asum(x):
    return x*(x+1)//2


def f(i):
    return asum(i)



n = int(input())
if n==1:
    print(1)
else :
    lo = 1
    hi = n
    while hi-lo>1:
        mid = (lo+hi)//2
        if f(mid) < n:
            lo = mid
        else:
            hi = mid

    i = lo
    n -= f(i)
    n -= 1 # 0-index
    cur = asum(i)+asum(i-1) + 1 + 2*n
    print(cur)

• Subtask 1: 0 / 100