Quipu (Inca counting system) calculator

Quipu Calculator

The Quipu is the numbering system of the ancient Incas. A number is represented by knots in a string, using a positional representation. Since the term “political correctness” was not discovered back then it meant that of all the mathematical bases in the world only base-10 was supported. So, if the number 586 was to be recorded on the string then six touching knots were placed near the right end of the string, a space was left, then eight touching knots for the tenths, another space, and finally 5 touching knots for the hundreds. Zeros are represented using a blank space. And this being maths, not politics, leading zeros are not allowed.

If @ is a knot and ~ is a space, then 12050 would become @~@@~~~@@@@@~~

Incas knew that system very well and possessed the knowledge to sum and multiply those numbers, but only the sailors who worked part time as math professors could tie such fine knots and not get the calculation wrong.

One day, Boko Borisuri, the most egocentric of all Incas, promised to solve this problem by building a calculator so everyone can calculate quickly. He was neither a sailor, nor a professor, though. So, naturally, he could not deliver and is now facing publish shaming (which, for him, is worse than death).

Help him by writing the calculator for him. Also, since the code will be distributed using a different, but equally mad knot system, keep it as short as possible.

Input

A string representing a mathematical expression with operands in the Quipu format above, separated by the plus [+] or the multiplication [*] sign. The expression can also include parenthesis to change order of operation.

Output

A string representing the result of the mathematical expression in Quipu format.

Example:

quipu_calculator("@~@@+@~@@@*@~~~~")
=> "@~@@@~@~@@"
quipu_calculator("@~~~~~@~~+@@~~~~~@@~~")
=> "@@@~~~~~@@@~~"

Leader board

The lower the score - the better. It is the shortest solution that wins.

If you're among the first 5 stop by out booth to claim your reward.

Winner!

Nickname: janosch-jo
   Score: 98

def quipu_calculator s
  "#{eval s.gsub(/@+~?|~~?/) { $&.count ?@}}".
  chars.map { |c|
    n = eval c
    n < 1 ? ?~ : ?@ * n
  } * ?~
end

Winner!

Nickname: remi
   Score: 100

def quipu_calculator s
  "#{eval s.gsub(/((@+)|~)~?/) { "#$2".size }}"
    .chars.map { |c| c[?0] ? ?~ : ?@ * c.to_i } * ?~
end

Winner!

Nickname: buhtum
   Score: 101

def quipu_calculator e
  eval(
      e.gsub(/(@+|~)~?/) { $1.count ?@ }
  ).to_s.chars.map { |d| d=eval d
  d == 0 ? ?~ : ?@ * d } * ?~
end

Winner!

Nickname: J-_-L
   Score: 102

def quipu_calculator a
"#{eval a.gsub(/~~|@+/){$&.count ?@}.tr ?~,''}".chars.map{|e|e<?1??~:?@*e.to_i}*?~
end

Winner!

Nickname: Joskov
   Score: 102

def quipu_calculator n
  eval(n.gsub(/(~|@+)~?/) { |i| i.count ?@ }).to_s.chars.map { |i| i == ?0 ? ?~ : ?@ * i.to_i } * ?~
end

Nickname: webit
   Score: 104

def quipu_calculator(s)
"#{eval s.gsub(/@+|~~/){ $&.count ?@}.tr ?~,''}".chars.map{|i| i < ?1 ? ?~ : ?@*i.to_i }*?~
end

Nickname: Cinti
   Score: 107

def quipu_calculator d
 eval(
    d.gsub(/@+|~~/) { |f| 
      f.count ?@ 
    }.tr ?~, ''
  ).to_s.chars.map { |n| 
    n == ?0 ? ?~ : ?@ * n.to_i
  } * ?~
end

Nickname: JJ
   Score: 111

def quipu_calculator s
  eval(s.gsub(/@+/, &:size).gsub(/~~/, ?0).tr ?~, '').to_s.chars.map { |c| c == ?0 ? ?~ : ?@ * c.to_i } * ?~
end

Nickname: yitsushi
   Score: 121

def quipu_calculator s
  eval(
    s.gsub(/~~/, '0').gsub(/@+/) { |m|
      m.size
    }.tr '~', ''
  ).to_s.chars.map { |n|
    l = n.to_i
    l < 1 ? '~' : '@' * l
  } * "~"
end

Nickname: sashe
   Score: 125

def quipu_calculator s
  eval(s.gsub(/@+/, &:size).gsub(/~~/, '0').gsub('~', '')).
    to_s.chars.
    map { |e| e != '0' ? '@' * e.to_i : '~' }.join '~'
end

Nickname: rambo
   Score: 129

def quipu_calculator n
  z = ->(i) { i > 0 ? ?@*i : ?~ }
  10.times { |i| i = 9-i; n.gsub! /~?#{z[i]}~??/, i.to_s }  
  eval(n).to_s.chars.map { |d| z[d.to_i] } * ?~
end

Nickname: timrogers
   Score: 131

def quipu_calculator q
  "#{eval(
    q.gsub(/(@+)/, &:size).
      gsub('~~', ?0).
      tr ?~, ''
  )}".
    gsub(/([1-9])/) { |d| ?@ * d.to_i + ?~ }.
    gsub(?0,"~~")[0..-2]
end

Nickname: martian
   Score: 147

def quipu_calculator n
  c = (1..9).reduce({?0=>'~~'}){|o,m|
    o[m.to_s]=?@*m
    o
  }
  eval(n.gsub(/(~~)|(~|@+)/) {|m| c.key(m)}).to_s.chars.map{|i|
    c[?0]=?~
    c[i]
  }*?~
end

Nickname: emrox
   Score: 153

def quipu_calculator(x)
  eval(x.gsub(/[@~]+/){|q|m=q.gsub(/~~/,'~0').split(?~);m.map{|e|e==?0?0:e.size}.join}).to_s.chars.map{|c|c=c.to_i;c>0??@*c :?~}*?~
end

Nickname: thesnapdragon
   Score: 233

def quipu_calculator(d)
  d.gsub(/\(|\)/,"").split(/\+|\*/).map{|e|e.gsub(/~~/, "~").split(/~/, -1).map(&:size).join}.each{|r| d = d.gsub(/[\@|~]/, "-").squeeze("-").sub /-/, "#{r}"}
  eval(d).to_s.split(//).map{|c| c == "0" ? "~" : "@"*c.to_i}.join "~"
end