Submission #1606938

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Source Code Expand

def kdp (numstr)
  #桁、れす、つかった
  dp = 20.times.map{2.times.map{Array.new(2, 0)}}
  dp[0][0][0] = 1
  numstr.length.times{|i|
    2.times{|j|
      lim = (j == 1)? 9 : numstr[i].to_i
      (lim+1).times{|d|
        less = (j==0&&d==lim)?0:1
        2.times{|k|
          used = (k==1||d==4||d==9)?1:0
          dp[i+1][less][used] += dp[i][j][k]
        }
      }
    }
  }
  dp[numstr.length].map{|t|t[1]}.inject(:+)
end

A,B = gets.split.map(&:chomp)
#A以上B以下なのでB-(A-1)らしい？
aun = kdp((A.to_i-1).to_s)
bun = kdp(B)
puts bun-aun

Submission Info

Judge Result