Parallel arrays in Ruby

Question

I have two arrays, one which stores candidate names, and another which stores the number of votes for said candidate. I'm trying to print the maximum amount of votes and the name of the corresponding candidate; instead of an output such as 92, 4 (number of votes, index of candidate), output something like 92, John.

This is as close as I've got to doing so:

puts "Candidates, index order: 0, 1, 2, 3, 4"
candidates.each { |x| puts x }
puts "Votes, index order: 0, 1, 2, 3, 4"
votes.each { |y| puts y }

votes.delete(nil)
puts "Maximum number of votes, followed by candidates array index."
puts votes.each_with_index.max { |x,y| x <=> y }

I'm successfully getting the index at which the max value is located, but how can I use that index to match the index of the candidates array in order to print a name rather than an index?

sawa · Accepted Answer · 2016-01-17 23:54:07Z

5

puts votes.zip(candidates).max_by(&:first)

answered Jan 17, 2016 at 23:54

sawa

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2 Comments

Jeremy Stone Over a year ago

FINALLY! I spent way too much time trying to figure this out. Thank you!

Cary Swoveland Over a year ago

That doesn't necessarily mean the time was wasted. btw, whenever you can use Enumerable#zip with two arrays of equal size you can alternatively use Array#transpose: [[10,23,6],["Bob", "Betty", "Bubba"]].transpose.max_by(&:first) #=> [23, "Betty"]. Another, less Ruby-like, way is mx = votes.max; [mx, candiates[votes.index(mx)].

Wand Maker · Accepted Answer · 2016-01-18 05:26:00Z

0

A one more way to do this is given below, this will work if you had multiple candidates with same votes.

indices = votes.collect.with_index {|ele, idx| idx if ele == votes.max}.compact
result = indices.map  do |m|
    [votes[m], candidates[m]]
end

edited Jan 18, 2016 at 5:26

answered Jan 18, 2016 at 5:20

Wand Maker

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