probelm36
基数変換がダサい。
Prelude> let d2b x = if (div x 2)/=0 then (d2b (div x 2))++[mod x 2] else [mod x 2] in sum [x|x<-[1..1000000],show x==reverse (show x),d2b x==reverse (d2b x)] 872187 it :: Integer (1.20 secs, 877606456 bytes)
基数変換がダサい。
Prelude> let d2b x = if (div x 2)/=0 then (d2b (div x 2))++[mod x 2] else [mod x 2] in sum [x|x<-[1..1000000],show x==reverse (show x),d2b x==reverse (d2b x)] 872187 it :: Integer (1.20 secs, 877606456 bytes)