MRECAMAN - Recaman’s Sequence


The Recaman’s sequence is defined by a0 = 0 ; for m > 0, a(m) = a(m−1) − m if the resulting a(m) is positive and not already in the sequence, otherwise a(m) = a(m−1) + m. The first few numbers in the Recaman’s Sequence is 0, 1, 3, 6, 2, 7, 13, 20, 12, 21, 11, 22, 10, 23, 9 · · · .

Given k, your task is to calculate a(k).

Input

The input consists of several test cases. Each line of the input contains an integer k where 0 ≤ k ≤ 500000. The last line contains an integer −1, which should not be processed.

Sample Input
7
10000
-1

Output

For each k given in the input, print one line containing a(k) to the output.

Sample output
20
18658


hide comments
nobody550: 2019-02-03 08:48:58

while using unordered_map, compile your code on gcc c++ 6.3

mr_robot_rb01: 2018-11-18 09:21:25

100th

Last edit: 2018-11-18 09:21:43
pnqcd: 2018-10-04 11:23:01

@adiyad1998 help

Last edit: 2019-03-25 14:11:54
pnqcd: 2018-10-04 11:21:28

@Ravi help

Last edit: 2019-03-25 14:12:26
adityad1998: 2018-07-02 12:03:39

Simple precomputation and maps!

ameyanator: 2018-03-22 22:45:43

Simple precomputation and then cout<<ans

v_pp_27: 2018-02-13 05:12:16

Maps and precalculation....!

Shubham Jadhav: 2017-05-15 12:04:42

My 150th :)

nilabja16180: 2017-03-12 11:09:48

Easy one!

naidumcl: 2017-02-01 19:10:26

Simple one..


Added by:~!(*(@*!@^&
Date:2009-02-23
Time limit:0.138s-0.778s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:Pre Shanghai 2004