scientific notation

def shift(num,exp)
  num = num.split(//)
  if exp < 0
    dotpos = 0
    num.each_with_index do
      |k,v| dotpos = v if k == "."
    end
    if exp.abs > dotpos
      (exp.abs - dotpos).times do
    num.insert(0,"0")
      end
      num.delete_if {|x| x == "."}
      num.insert(0,".")
    else

      num.delete_if {|x| x == "."}
      num.insert(dotpos - exp.abs,".")
    end
  else
    dotpos = 0
    num.each_with_index do
      |k,v| dotpos = v+1 if k == "."
    end
    exlen = num.length-dotpos
    num.delete_if {|x| x == "."}
    (exp-exlen).times do
      num.insert((num.length),0)
    end
  end
  num.join()
end

def to_float(num)
  num = num.split(//)
  orignum,exp = "",""
  endex,startex = 0,0
  num.each_with_index {|k,v| endex = v and break if k == "x" or k == " "}
  num.each_with_index {|k,v| startex = v and break if k == "^"}
  num.each_with_index {|k,v| orignum << k if v < endex }
  num.each_with_index {|k,v| exp << k if v > startex}
  return 10 ** exp.to_i if orignum == "1"
  return shift(orignum,exp.to_i)
end

def to_sci(num)
  num = num.to_s.split(//)
  if num.join.to_f > 1
    orignum,explen = "",0
    startget = false
    num.reverse.each {|x| startget = true if x != "0"; orignum << x if startget}
    orignum = orignum.reverse
    orignum = orignum.split(//).insert(1,".").join()
    return orignum << " x 10^" << (num.length-1).to_s
  else
    return num.to_s << " x 10^0"  if num.join().to_f == 1.0
    dotpos,fnumpos,explen = 0,0,0
    orignum = ""
    num.each_with_index {|k,v| dotpos = v if k == "."}
    num.each_with_index do |k,v|
      if k != "0" and k != "."
    fnumpos = v
    break
      end
    end
    num.each_with_index {|k,v| orignum << k if v >= fnumpos}
    orignum = orignum.split(//).insert(1,".").join()
    num.each_with_index {|k,v| explen += 1 if dotpos < v and v <= fnumpos}
    return orignum << " x 10^" << (explen*-1).to_s
  end
end

puts to_sci("632194030000")
puts to_float("6.3219403 x 10^11")