sort, .array and folding on immutable data (finding most common character in column of matrix)

[Ali via Digitalmars-d-learn]

On Monday, 19 December 2016 at 12:45:48 UTC, Nicholas Wilson 
wrote:
>
> Ah, oh well. It was nice in theory.
>

Indeed. Thank you for trying Nicholas :)

>
> auto word = data.map!(reduce!max).array.map!"a[1]".array;
>
> you want
>
> auto word = data.map!"a[1]".map!(reduce!max).array;
>

Problem max has to performed on the frequency part of the tuple 
and "word" has to result in a concatenation of all the character 
parts of the highest frequencied letters. So that up there will 
result in "word" = 364782 // or something.