Find every digit from the largest column

Question

Here's a relatively simple challenge for you:

Given a list of positive integers:

• Line them up in a grid, and sum each column. For example, if the input was [123, 7, 49, 681], the grid would look like this:

   1  2  3
   7 
   4  9 
   6  8  1 
  

  And the sum of each column would be [18, 19, 4]:

   1  2  3
   7 
   4  9 
   6  8  1 
   --------
   18 19 4
  

• Find the maximum of these sums, which in this case would be 19, and then

• Output every digit that is at the same index as this maximum column. In this case, that would be

  2
  9
  8
  

  You do not have to output these numbers in any particular order. Note that there are only three outputs, even though we had 4 inputs. In the case of a tie, pick the earliest index. For example, if the input was [25, 223, 302], your grid is:

  2  5
  2  2  3
  3  0  2
  -------
  7  7  5
  

  You should output

  2
  2
  3
  

You can print these numbers in any format you like. List format, newline separated, space separated, etc. You may not take the input as a 2D array of digits, e.g.

[[1, 2, 3],
[7],
[4, 9],
[6, 8, 1]

But other than that, you can take input as a list of strings, a list of digits, or any other reasonable format.

You may also assume that all inputs will be valid and contain at least two numbers.

As usual, the shortest answer in bytes wins!

Test IO:

#Input                      #Output
[1, 11, 111, 1111]      --> [1, 1, 1, 1]
[1, 12, 123]            --> [2, 2]
[987654321, 111]        --> [9, 1]
[111, 123456789]        --> [9]
[4, 8, 15, 16, 23, 42]  --> [4, 8, 1, 1, 2, 4]
[4, 8, 12, 26, 27, 38]  --> [2, 6, 7, 8]
[24, 53]                --> [2, 5]
[12, 304, 506]          --> [4, 6]
[30, 285, 121]          --> [0, 8, 2]

Answer 1

Haskell, 63 bytes

import Data.Lists
argmax sum.transpose.map(map(read.pure).show)

Usage example: argmax sum.transpose.map(map(read.pure).show) $ [12,304,506] -> [4,6].

How it works:

                     map                       -- for each number
                         map(read.pure).show   -- turn into list of digits
           transpose                           -- transpose the list of list
argmax sum                                     -- find the element with the
                                               -- largest sum

Answer 2

Jelly, 6 bytes

DZṚSÞṪ

Try it online!. This is a relatively straightforward implementation of the question.

D              Convert each number in the input to a list of digits, e.g.
               [353, 2247] -> [[3, 5, 3], [2, 2, 4, 7]]
 Z             Zip the lists together, e.g. [[3, 2], [5, 2], [3, 4], [7]]
  Ṛ            Reverse the list of lists so that first occurrences are now
               at the end, e.g. [[7], [3, 4], [5, 2], [3, 2]]
   SÞ          Sort by sum - this uses Python's sorted function, which is stable
               so equal elements end up in order of appearance, e.g.
               [[3, 2], [7], [3, 4], [5, 2]]
     Ṫ         Tail - get the last element, e.g. [5, 2]

Answer 3

Ruby, 100 97 bytes

a=$<.map &:chomp
puts a.map(&:size).max.times.map{|i|a.map{|e|e[i]}.compact}.max_by{|e|eval e*?+}

Answer 4

Mathematica 82 bytes

This pads the digits of each number with x's to the right, transposes the matrix, removes the dummy x's, orders by sum of the digits and takes the greatest.

SortBy[#~Select~NumberQ&/@Transpose[PadRight[#,30,x]&/@IntegerDigits@#],Tr][[-1]]&

---

There ought to be some way to use the superscript-T form of Transpose to save a few bytes.

Answer 5

Perl, 49 48 bytes

Includes +1 for -p

Run with the input on STDIN, prints to STDOUT the column numbers prefixed by +

lcolumn.pl
123
7 
49 
681

lcolumn.pl:

#!/usr/bin/perl -p
s/./@;[@-].="+$&"/eg}{($_)=sort{eval"$b<=>$a"}@

Answer 6

Javascript (ES6), 108 103 100 bytes

It's a bit verbose and could probably be golfed some more with a different approach. I wish I could get rid of this .filter(n=>n).

Saved 5 bytes thanks to Neil
Saved 3 bytes thanks to edc65

l=>l.map(n=>[...n].map((d,x)=>(m=(s[x]=(s[x]|0)-d)<m?s[c=x]:m,d)),s=[m=0]).map(n=>n[c]).filter(n=>n)

Demo

let f =
l=>l.map(n=>[...n].map((d,x)=>(m=(s[x]=(s[x]|0)-d)<m?s[c=x]:m,d)),s=[m=0]).map(n=>n[c]).filter(n=>n)

console.log(f(["1", "11", "111", "1111"]).join`,`);          // --> [1, 1, 1, 1]
console.log(f(["1", "12", "123"]).join`,`);                  // --> [2, 2]
console.log(f(["987654321", "111"]).join`,`);                // --> [9, 1]
console.log(f(["111", "123456789"]).join`,`);                // --> [9]
console.log(f(["4", "8", "15", "16", "23", "42"]).join`,`);  // --> [4, 8, 1, 1, 2, 4]
console.log(f(["4", "8", "12", "26", "27", "38"]).join`,`);  // --> [2, 6, 7, 8]
console.log(f(["24", "53"]).join`,`);                        // --> [2, 5]
console.log(f(["12", "304", "506"]).join`,`);                // --> [4, 6]
console.log(f(["30", "285", "121"]).join`,`);                // --> [0, 8, 2]

Answer 7

Pyth, 5 8 bytes

esDsMM.T

Takes in input as a list of strings, outputs as a nothing-separated list of digits.

Try it online!

Explanation:

      .T  Transpose input to zip together corresponding columns
   sMM    Cast to digit lists
 sD       sort(D) by (s)um
e         take last element, implicitly print

Answer 8

Pyth, 11 bytes

h.MsZ.TmjdT

A program that takes input of a list of integers on STDIN and prints a list.

Try it online

How it works

h.MsZ.TmjdT  Program. Input: Q
        j T   Yield the base-10 representation, giving a list of digits
       m d   Map that over Q (implicit input fill)
     .T      Justified transpose, giving each column as a list
 .MsZ        Filter the above by maximum sum
h            First element of above
             Implicitly print

Answer 9

JavaScript (ES6), 90

(l,x)=>[...l+0].map((t,i)=>l.map(n=>(n=n[i])&&(v-=n,t.push(n)),v=t=[])|v>=x||(x=v,r=t))&&r

f=(l,x)=>[...l+0].map((t,i)=>l.map(n=>(n=n[i])&&(v-=n,t.push(n)),v=t=[])|v>=x||(x=v,r=t))&&r

;[
 [[123, 7, 49, 681]       , [2,9,8]]
,[[25, 223, 302]          , [2, 2, 3]]
,[[1, 11, 111, 1111]      , [1, 1, 1, 1]]
,[[1, 12, 123]            , [2, 2]]
,[[987654321, 111]        , [9, 1]]
,[[111, 123456789]        , [9]]
,[[4, 8, 15, 16, 23, 42]  , [4, 8, 1, 1, 2, 4]]
,[[4, 8, 12, 26, 27, 38]  , [2, 6, 7, 8]]
,[[24, 53]                , [2, 5]]
,[[12, 304, 506]          , [4, 6]]
,[[30, 285, 121]          , [0, 8, 2]]]
.forEach(t=>{
  var i=t[0], o=t[1], r, ok
  i=i.map(x=>x+'') // convert i to a string list
  r=f(i) 
  ok = (r+'')==(o+'') // compare r and o as comma separated strings
  console.log(ok?'OK':'KO', i+' -> '+ r)
  
})

Answer 10

Pyth - 9 bytes

esD_.TjRT

Test Suite.