David Alan Black <dblack / candle.superlink.net> writes:


String mixes in Enumerable, so each_with_index is available.

     def common4(w1, w2)
       c = 0
       w1.each_with_index { |ch, i| c += 1 if w2[i] == ch }
       c
     end

On my box, this is over twice as fast as the others.

                user     system      total        real
            0.570000   0.000000   0.570000 (  0.573853)
            0.550000   0.000000   0.550000 (  0.505016)
            0.540000   0.000000   0.540000 (  0.503355)
            0.200000   0.000000   0.200000 (  0.198964)


Regards


Dave