Communities

Writing

Codidact Meta

The Great Outdoors

Photography & Video

Scientific Speculation

Cooking

Electrical Engineering

Judaism

Languages & Linguistics

$Mathematics$

tag:snake search within a tag

answers:0 unanswered questions

user:xxxx search by author id

score:0.5 posts with 0.5+ score

"snake oil" exact phrase

votes:4 posts with 4+ votes

created:<1w created < 1 week ago

post_type:xxxx type of post

Search help

Notifications

Mark all as read See all your notifications »

Challenges Q&A Sandbox Meta

Challenges

Posts Tags Edits

Post Challenge

Comments on Find n Niven Numbers

Parent

Find n Niven Numbers

+7

−0

Challenge

A Niven number is a positive integer which is divisible by the sum of its digits.

For example, 81 -> 8+1=9 -> 81%9=0.

Your task is to find the first n Niven numbers, given n.

Tests

Reference implementation(takes input)

first 16 values:

0 => 1
1 => 2
2 => 3
3 => 4
4 => 5
5 => 6
6 => 7
7 => 8
8 => 9
9 => 10
10 => 12
11 => 18
12 => 20
13 => 21
14 => 24
15 => 27

code-golf math sequence

posted over 2 years ago

CC BY-SA 4.0

2y ago by user‭

Razetime‭

2860 reputation 42 65 321 83

Raw

Markdown

History

is a duplicate

This question has been asked before and has already been answered. It should be marked as a duplicate.

Please enter the URL of the proposed duplicate in the details field below.

not constructive

This question cannot be answered in a way that is helpful to anyone. It's not possible to learn something from possible answers, except for the solution for the specific problem of the asker.

+4

−0

Scala, 52 bytes ```scala S …

2y ago

+3

−0

Vyxal, 4 bytes ``` ‡∑Ḋȯ ``` …

2y ago

+2

−0

Python, 98 bytes ```python …

2y ago

+1

−0

x86-64 machine code, 36 bytes …

2y ago

+1

−0

Ruby, 56 bytes p (1..).lazy …

2y ago

+1

−0

Factor, 147 bytes ``` USIN …

2y ago

+0

−0

Japt, 10 bytes ÈvXìx}jU …

2y ago

2 comment threads

tangent: Niven? (2 comments)

Alternate output formats (2 comments)

Post

+2

−0

Python, 98 bytes

from itertools import*
f=lambda n:[*islice(filter(lambda k:k%sum(map(int,str(k)))==0,count(1)),n)]

itertools.count() generates integer numbers starting from 1,
filter() filters out the Niven numbers,
itertools.islice() limits the result to n items,
and [*...] collects the numbers in a list.

posted about 2 years ago

CC BY-SA 4.0

2y ago

__blackjack__‭

51 reputation 0 5 5 4

Copy Link

Raw

Markdown

History

1 comment thread

Without itertools (3 comments)

Peter Taylor‭ wrote about 2 years ago

copy link

The sum(map(int trick is shorter than I'd managed, but itertools is expensive. As a one-liner, a recursive lambda gets 76: f=lambda n,i=1,a=[]:a if a[n-1:]else f(n,i+1,a+[i][i%sum(map(int,str(i))):]). But if you don't insist on a list, the best I've found is an explicit loop for 73: def f(n,i=0): while n: i+=1 if i%sum(map(int,str(i)))<1:yield i;n-=1 where the tabs also indicate newlines