Grid all paths problem

Today I saw a post describing a "count all paths" problem and solutions to it written in Ruby, C, and Go: http://rayhightower.com/blog/2016/04/11/comparing-ruby-c-and-go/

I decided to try a (one-liner) solution in Crystal: https://github.com/dkhofer/sandbox/blob/master/crystal/all_paths.cr

The payoff:

$ crystal build crystal/all_paths.cr --release
$ time ./all_paths
184756

real	0m0.012s
user	0m0.007s
sys	    0m0.004s

This is very nearly as fast as the C code! I think this example shows, at least for problems of this scale, that the syntax of Go and C is not what makes them superior in performance to Ruby. It's mainly "just" that they have compilers. Well, and a popcount function, which Crystal has but Ruby does not.

Other languages

To confirm this was a fair comparison, I ran the Ruby, C, and Go code on my laptop too.

Ruby:

$ time ruby/all_paths.rb
184756

real	0m3.942s
user	0m3.754s
sys	    0m0.056s

C:

$ gcc all_paths.c -o all_paths
$ time ./all_paths
184756

real	0m0.010s
user	0m0.007s
sys	    0m0.002s

Go:

$ go get github.com/cznic/mathutil
$ go build ./all_paths.go
$ time ./all_paths
184756

real	0m0.013s
user	0m0.008s
sys	    0m0.004s