Completed problem 2 and using guard to re-run specs.

Author: deepakhb2

Gemfile

@@ -5,6 +5,6 @@ source "https://rubygems.org"
 git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
 # gem "rails"
-gem "rspec"
-gem "byebug"
-gem "rake"
+gem 'rspec'
+gem 'rake'
+gem 'guard-rspec'

Gemfile.lock

@@ -1,9 +1,40 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    byebug (11.1.3)
+    coderay (1.1.3)
     diff-lcs (1.4.4)
+    ffi (1.14.2)
+    formatador (0.2.5)
+    guard (2.16.2)
+      formatador (>= 0.2.4)
+      listen (>= 2.7, < 4.0)
+      lumberjack (>= 1.0.12, < 2.0)
+      nenv (~> 0.1)
+      notiffany (~> 0.0)
+      pry (>= 0.9.12)
+      shellany (~> 0.0)
+      thor (>= 0.18.1)
+    guard-compat (1.2.1)
+    guard-rspec (4.7.3)
+      guard (~> 2.1)
+      guard-compat (~> 1.1)
+      rspec (>= 2.99.0, < 4.0)
+    listen (3.3.3)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
+    lumberjack (1.2.8)
+    method_source (1.0.0)
+    nenv (0.3.0)
+    notiffany (0.1.3)
+      nenv (~> 0.1)
+      shellany (~> 0.0)
+    pry (0.13.1)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
     rake (12.3.3)
+    rb-fsevent (0.10.4)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)
       rspec-expectations (~> 3.9.0)
@@ -17,12 +48,14 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
     rspec-support (3.9.3)
+    shellany (0.0.1)
+    thor (1.0.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  byebug
+  guard-rspec
   rake
   rspec
 

lib/Problems/daily-coding-problems/problem002.rb

@@ -0,0 +1,59 @@
+# This problem was asked by Uber.
+#
+# Given an array of integers, return a new array such that each element at
+# index i of the new array is the product of all the numbers in the original
+# array except the one at i.
+#
+# For example, if our input was [1, 2, 3, 4, 5], the expected output would be
+# [120, 60, 40, 30, 24]. If our input was [3, 2, 1], the expected output would
+# be [2, 3, 6].
+#
+# Follow-up: what if you can't use division?
+class Problem002
+  # O(n) space and time complexity
+  def self.solution(values)
+    result, size = [], values.size
+    prefix_products = []
+    (0...size).each do |i|
+      if prefix_products.empty?
+        prefix_products.append(values[i])
+      else
+        prefix_products.append(prefix_products[-1] * values[i])
+      end
+    end
+    suffix_products = []
+    values.reverse.each do |val|
+      if suffix_products.empty?
+        suffix_products << val
+      else
+        suffix_products << suffix_products[-1] * val
+      end
+    end
+    suffix_products = suffix_products.reverse
+    (0...size).each do |i|
+      if(i==0)
+        result.append(suffix_products[i + 1])
+      elsif(i == size-1)
+        result.append(prefix_products[i - 1])
+      else
+        result.append(prefix_products[i-1] * suffix_products[i+1])
+      end
+    end
+    return result
+  end
+
+  # O(n^2) time complexity
+  def self.solution1(values)
+    result, size = [], values.size
+    (0...size).each do |i|
+      mult = 1
+      (0...size).each do |j|
+        unless(i == j)
+          mult *= values[j]
+        end
+      end
+      result << mult
+    end
+    return result
+  end
+end

spec/Problems/daily-coding-problems/Problem002_spec.rb

@@ -0,0 +1,27 @@
+# This problem was asked by Uber.
+#
+# Given an array of integers, return a new array such that each element at
+# index i of the new array is the product of all the numbers in the original
+# array except the one at i.
+#
+# For example, if our input was [1, 2, 3, 4, 5], the expected output would be
+# [120, 60, 40, 30, 24]. If our input was [3, 2, 1], the expected output would
+# be [2, 3, 6].
+#
+# Follow-up: what if you can't use division?
+
+describe Problem002 do
+  context 'Valid inputs' do
+    it '#solution inc order number' do
+      values = [1, 2, 3, 4, 5]
+      expected_values = [120, 60, 40, 30, 24]
+      expect(described_class.solution(values)).to eq(expected_values)
+    end
+
+    it '#solution desc order number' do
+      values = [3, 2, 1]
+      expected_values = [2, 3, 6]
+      expect(described_class.solution(values)).to eq(expected_values)
+    end
+  end
+end

spec/Problems/daily-coding-problems/problem1_spec.rb spec/Problems/daily-coding-problems/problem001_spec.rb

@@ -1,6 +1,9 @@
 require_relative '../lib/Algorithm-Sorting/bubble_sort.rb'
 require_relative '../lib/Data-Structures-Array/my_array'
 require_relative '../lib/Algorithm-Sorting/insertion_sort.rb'
+require_relative '../lib/Problems/daily-coding-problems/problem1.rb'
+require_relative '../lib/Problems/daily-coding-problems/problem002.rb'
+require_relative '../lib/Problems/daily-coding-problems/problem235.rb'
 
 # This file was generated by the `rspec --init` command. Conventionally, all
 # specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.