Re: Ruby Quiz - Challenge #5 - Crypto Mining - Find the Winning Lucky Number - Nonce (=Number used ONCE) for the Proof-of-Work (PoW) Hash (SHA-256)

Gerald Bauer wrote:
> Challenge #5 -Crypto Mining - Find the Winning Lucky Number - Nonce
> (=Number used ONCE) for the Proof-of-Work (PoW) Hash (SHA-256)

$ ruby lib/005.rb ; ruby lib/005.rb ; ruby lib/005.rb
Run options: --seed 10469
# Running:
.
Finished in 0.003223s, 310.3069 runs/s, 620.6138 assertions/s.
1 runs, 2 assertions, 0 failures, 0 errors, 0 skips
Run options: --seed 50672
# Running:
.
Finished in 0.003319s, 301.2743 runs/s, 602.5487 assertions/s.
1 runs, 2 assertions, 0 failures, 0 errors, 0 skips
Run options: --seed 19649
# Running:
.
Finished in 0.003258s, 306.9501 runs/s, 613.9003 assertions/s.
1 runs, 2 assertions, 0 failures, 0 errors, 0 skips

$ cat lib/005.rb
require_relative '../005/test.rb'
class RubyQuizTest
  def compute_nonce(data)
    0.upto(Float::INFINITY) do |nonce|
      break nonce if sha256("#{nonce}#{data}", 2)==0
    end
  end
  require 'inline'
  inline do |builder|
    builder.include '<string.h>'
    builder.include '<openssl/sha.h>'
    builder.c <<-END
      int sha256(char * s, int difficulty) {
        unsigned char * d = SHA256((unsigned char *)s, strlen(s), 0);
        for(int i=0; i<difficulty; i++) if (d[i] != 0) return -1;
        return 0;
      }
    END
  end
end
RubyQuizTest.new('fjc')



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