JLILLY sorting

sort.rb

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+module Sort
+
+  def self.selection_sort(array)
+    #array.sort
+
+    temp_num = 0
+    min_num = 0
+    min_index=0
+
+    for h in 0...array.length
+        min_num = array[h]
+      for i in h...array.length-1
+        if array[i+1]<min_num
+          min_num = array[i+1]
+          min_index = i+1
+        end
+      end
+      temp_num = array[h]
+      array[h] = min_num
+      array[min_index] = temp_num
+    end
+    array
+  end
+
+  def self.countdown(n)
+    puts n
+    countdown(n-1) if n >0
+  end
+
+  def self.fizzbuzz(n)
+    fizzbuzz(n-1) if n>0
+    puts n%3==0 && n!=0 ? "fizz" : n%5==0 && n!=0 ? "buzz" : n
+  end
+
+  def self.exp(a,b)
+    return 1 if b<=0
+    a*exp(a,b-1)
+  end
+
+  def self.collatz(n)
+    puts n
+    return if n==1
+    return collatz(n/2) if n%2 == 0 
+    collatz(3*n+1)
+  end
+
+
+end

spec/sort_spec.rb

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+require 'rubygems'
+require 'rspec'
+require_relative '../sort.rb'
+
+
+describe 'Sort' do |variable|
+  describe '.selection_sort' do
+    it "returns an empty array" do
+      expect(Sort.selection_sort([])).to eq([])
+    end
+  end
+
+  describe '.selection_sort' do
+    it "successful with duplicates" do
+      expect(Sort.selection_sort([4,5,2,3,8,9,1,2,2])).to eq([4,5,2,3,8,9,1,2,2].sort)
+    end
+  end
+
+  describe '.selection_sort' do
+    it "works with negatives" do
+      expect(Sort.selection_sort([-1,-5,2,6,44,95,-4])).to eq([-1,-5,2,6,44,95,-4].sort)
+    end
+  end
+
+  describe '.selection_sort' do
+    rand_arr = (0..20000).to_a.map!{|x| x = (rand()*1000).to_i }
+
+    it "works for large unordered arrays." do
+      expect(Sort.selection_sort(rand_arr)).to eq(rand_arr.sort)
+    end
+  end
+
+end