exercism 30-35

Author: kumar91gopi

README.md

@@ -2,7 +2,7 @@
 > ### Featured on [Awesome-algorithms](https://github.com/tayllan/awesome-algorithms) & [Ruby-bookmarks](https://github.com/dreikanter/ruby-bookmarks)
 
 This repository contains Ruby implementation of various Algorithms and Data structures and
-solution of many challenges of [Leetcode](https://leetcode.com/),[Exercism](https://exercism.org/),[HackerRank](https://www.hackerrank.com) and [Codility](https://codility.com)
+solution of many challenges of [Leetcode](https://leetcode.com/), [Exercism](https://exercism.org/), [HackerRank](https://www.hackerrank.com) and [Codility](https://codility.com)
 
 ## Content : 
 * [Searching](#searching)

exercism/clock.rb

@@ -0,0 +1,38 @@
+# Problem: https://exercism.org/tracks/ruby/exercises/clock
+
+#Solution
+class Clock
+    attr_accessor :hour, :minute
+    
+    def initialize(hour:0,minute: 0)
+      @hour = (hour+(minute/60)) % 24
+      @minute = minute%60
+    end
+    
+    def to_s
+     display_time(@hour,@minute)
+    end
+    
+    def ==(other)
+      self.class == other.class &&
+        @hour == other.hour &&
+        @minute == other.minute
+    end
+
+    def +(other)
+      raise TypeError unless self.class == other.class
+      Clock.new(hour:@hour+other.hour,minute:@minute+other.minute)
+    end
+
+     def -(other)
+      raise TypeError unless self.class == other.class
+      Clock.new(hour:@hour-other.hour,minute:@minute-other.minute)
+    end
+
+    private
+    def display_time(hour,minute)
+      display_hour = hour <10 ? "0#{hour}" : hour
+      display_minute = minute<10 ? "0#{minute}" : minute
+      "#{display_hour}:#{display_minute}"
+    end
+end

exercism/gigasecond.rb

@@ -0,0 +1,8 @@
+# problem: https://exercism.org/tracks/ruby/exercises/gigasecond
+
+#Solution
+class Gigasecond
+    def self.from(input_date)
+      input_date+10**9
+    end
+end

exercism/luhn.rb

@@ -0,0 +1,59 @@
+#Problem :https://exercism.org/tracks/ruby/exercises/luhn
+
+#Solution 1
+class Luhn
+    def self.valid?(card_num)
+      is_index_odd = true
+      card_len = 0
+      sum=0
+      for i in (card_num.length-1).downto(0)
+        next if card_num[i]==" "
+        return false if card_num[i]<"0" or card_num[i]>"9"
+        card_len+=1
+        digit = is_index_odd ? card_num[i].to_i : (card_num[i].to_i*2)
+        digit = digit>9 ? digit-9 : digit
+        sum+=digit
+        is_index_odd = !is_index_odd
+      end
+      sum%10==0 and card_len>1
+    end
+end
+
+#Solution 2
+# Toggling multiplier between one and two
+class Luhn
+    def self.valid?(card_num)
+      multiplier = 2
+      card_len = 0
+      sum=0
+      for i in (card_num.length-1).downto(0)
+        next if card_num[i]==" "
+        return false if card_num[i]<"0" or card_num[i]>"9"
+        card_len+=1
+        multiplier = 3-multiplier
+        digit = (card_num[i].to_i*multiplier)
+        digit = digit>9 ? digit-9 : digit
+        sum+=digit
+      end
+      sum%10==0 and card_len>1
+    end
+end
+
+#Solution 3
+class Luhn
+    def self.valid?(card_num)
+      card_num = card_num.gsub(/\s/,'')
+      return false unless card_num.scan(/\D/).empty?
+      card_num_len = card_num.length
+      return false if card_num_len<=1
+      card_digits =card_num.reverse.chars.map(&:to_i)
+      multiplier = 2
+      for i in 0...card_num_len
+        multiplier = 3-multiplier #This will toggle between 1 and 2
+        card_digits[i]*=multiplier
+        card_digits[i]= card_digits[i]-9 if  card_digits[i]>9
+      end
+      card_digits.sum%10==0
+    end
+end
+

exercism/tournament.rb

@@ -0,0 +1,52 @@
+#Problem: https://exercism.org/tracks/ruby/exercises/tournament
+
+#Solution
+class Tournament
+    def self.tally(input)
+      matches = input.split("\n")
+      point_table = {}
+      matches.each do |match_str|
+        team1,team2,result = match_str.split(";")
+        self.set_team_data(team1,point_table) unless point_table.has_key?(team1)
+        self.set_team_data(team2,point_table) unless point_table.has_key?(team2)
+        point_table[team1][:MP]+=1
+        point_table[team2][:MP]+=1
+        if result == "win"
+          point_table[team1][:W]+=1
+          point_table[team1][:P]+=3
+          point_table[team2][:L]+=1
+        elsif result=="loss"
+          point_table[team2][:W]+=1
+          point_table[team2][:P]+=3
+          point_table[team1][:L]+=1
+        elsif result=="draw"
+          point_table[team1][:D]+=1
+          point_table[team2][:D]+=1
+          point_table[team1][:P]+=1
+          point_table[team2][:P]+=1
+        else
+          raise InputError
+        end
+      end
+      self.format_scorebaord(point_table)
+    end
+
+    private
+    def self.set_team_data(team,point_table)
+      point_table[team] = { "MP":0, "W":0, "L":0 , "D":0, "P":0 }
+    end
+    
+    def self.format_scorebaord(point_table)
+        point_table = point_table.sort_by{|team,score| [-score[:P],team]}
+        formatted = point_table.map do |team, result|
+          played = result[:MP].to_s.rjust(2)
+          points = result[:P ].to_s.rjust(2)
+          wins   = result[:W ].to_s.rjust(2)
+          draws  = result[:D ].to_s.rjust(2)
+          losses = result[:L ].to_s.rjust(2)
+        "#{team.ljust(30)} | #{played} | #{wins} | #{draws} | #{losses} | #{points}\n"
+        end
+        header = "Team                           | MP |  W |  D |  L |  P\n"
+        header + formatted.join
+    end
+end

exercism/twelve_days.rb

@@ -0,0 +1,36 @@
+#Problem: https://exercism.org/tracks/ruby/exercises/twelve-days
+
+#Solution
+class TwelveDays
+    DAYS = {
+            1=>["first","a Partridge in a Pear Tree"],
+            2=>["second","two Turtle Doves"],
+            3=>["third","three French Hens"],
+            4=>["fourth","four Calling Birds"],
+            5=>["fifth","five Gold Rings"],
+            6=>["sixth","six Geese-a-Laying"],
+            7=>["seventh","seven Swans-a-Swimming"],
+            8=>["eighth","eight Maids-a-Milking"],
+            9=>["ninth","nine Ladies Dancing"],
+            10=>["tenth","ten Lords-a-Leaping"],
+            11=>["eleventh","eleven Pipers Piping"],
+            12=>["twelfth","twelve Drummers Drumming"]
+    }
+    def self.song
+      song = ""
+      base_line = "On the %{ith} day of Christmas my true love gave to me: %{phrase}.\n"
+      for i in 1..12
+        phrase = ""
+        j =i
+        while j>0
+          phrase+="and " if j==1 and i!=1
+          phrase+=DAYS[j][1]
+          phrase+=", " unless j==1
+          j-=1
+        end
+        song+="\n" unless song==""
+        song+= base_line % {ith:DAYS[i][0],phrase:phrase}
+      end
+      song
+    end
+end