Time - HannahT

Rakefile

@@ -1,9 +1,9 @@
-require 'rake/testtask'
+require "rake/testtask"
 
 Rake::TestTask.new do |t|
   t.libs = ["lib"]
   t.warning = true
-  t.test_files = FileList['test/*_test.rb']
+  t.test_files = FileList["test/*_test.rb"]
 end
 
 task default: :test

lib/array_intersection.rb

@@ -1,3 +1,32 @@
 def intersection(list1, list2)
-  raise NotImplementedError, "Intersection not implemented"
-end
+  matching_dudes = []
+
+  list1.each do |item1| # outer loop - 1st time - item1 = 2, 2nd time - 4
+    list2.each do |item2| # inner loop - 1st time - item2 - 2, 2ndtime - item2 =3, 3rd time - item2 = 5, 4thtime, item2 - 7
+      # 2nd time we run outer loop, comparing 4 to all these guys over again - # inner loop - 1st time - item2 - 2, 2ndtime - item2 =3, 3rd time - item2 = 5, 4thtime, item2 - 7
+      if item1 == item2 # these are both integers - they are elements inside the array
+        matching_dudes << item1 # this can be item1 or item2, doesn't matter since they're the same!
+      end
+    end
+  end
+  return matching_dudes
+end
+
+list1 = [2, 4, 6, 8]
+list2 = [2, 3, 5, 7]
+puts intersection(list2, list1)
+
+# this is for 1 number, 1 array
+# initialize empty array
+# iterate over array
+# if number == item in array
+# put item in new array
+# return new array
+
+# this is for 2 arrays
+# initialize empty array (to put the dudes that match into)
+# iterate over first array
+# inside that loop, iterate over 2nd array
+# if item in 1st array == item in 2nd array
+# put item in new array (the one w/ matching dudes)
+# return new array!

lib/palindrome_permutation.rb

@@ -1,4 +1,23 @@
-
+require_relative "permutations.rb"
+# Added a new test:)
 def palindrome_permutation?(string)
-  raise NotImplementedError, "palindrome_permutation? not implemented"
-end
+  hash = making_string_into_hash(string)
+  number_of_time_count_is_odd = 0
+  hash.each do |letter, count|
+    number_of_time_count_is_odd += 1 if count.odd?
+    # number_of_time_count_is_odd += 1 if count % 2 == 1 (another method to use instead)
+  end
+  return number_of_time_count_is_odd <= 1
+end
+
+# create a var of hash and set it == the helper method from permutations.rb making_string_into_hash(string)
+# (since you want to change the string into hash with key: value, ie, letter: count)
+# create (number_of_time_count_is_odd) var and set it == to 0
+# use .each method on the hash to get the number of count number
+# use if statment to see if the number count is odd or even number
+# looking at the test, a word to be a palindrom needs:
+# either be an even number || odd with just one nubmer example "racecar"
+# if the stored count amount == even number or has one odd number
+# return true to palindrome
+# return true to empty string
+# return false for anything else

lib/permutations.rb

@@ -1,4 +1,49 @@
-
 def permutations?(string1, string2)
-  raise NotImplementedError, "permutations? not implemented"
-end
+  if string1.length != string2.length
+    return false
+  end
+  hash1 = making_string_into_hash(string1)
+  hash2 = making_string_into_hash(string2)
+  if hash1 == hash2
+    return true
+  end
+  return false
+end
+
+# created a helper method
+def making_string_into_hash(string)
+  empty_hash = {}
+  string.each_char do |char|
+    # .each_char work for string...(to iterater over a string, .each will work on hash and array)
+    if empty_hash[char] # {'l' => 1}
+      empty_hash[char] += 1 # {'l' => 2}
+    else
+      empty_hash[char] = 1
+    end
+  end
+  return empty_hash
+end
+
+puts(making_string_into_hash("hello"))
+puts(making_string_into_hash("elloh"))
+
+# permutations?("hello", "ehllo") => true ["h", "e", ]
+# hello - ehllo - helo heelo oohel
+# h - 1,  e -1, l -2, o -1
+# heelo h -1 e -2 l -1, o -1
+# permutations?("pasta", "atsap") => true
+# permutations?("Pizza", "Pasta") => false
+# permutations?("", "") => true
+
+# check if the two strings have the same length
+# if the length is not ==, return false
+# if length is equal then
+# parse the two sting into key value pair
+# to do the parsing, separate the sring into char
+# count how many times the char exist and assign number
+# initialize an empty hash, {} no keys.
+# to count the char, create a loop .each_char h, e, l, l, o
+# on our first loop through, h is our character. 'h' => 1
+# if 'h' is not in the hash, we need to add it
+# if 'h' is in the hash, then we need to +1 the value
+# then compare the two hashes that are created

notes.md

@@ -0,0 +1,109 @@
+QUESTION 1: 
+
+def intersection(list1, list2)
+  matching_dudes = []
+  # this is for 1 number, 1 array
+  # initialize empty array
+  # iterate over array
+  # if number == item in array
+  # put item in new array
+  # return new array
+
+  # this is for 2 arrays
+  # initialize empty array (to put the dudes that match into)
+  # iterate over first array
+  # inside that loop, iterate over 2nd array
+  # if item in 1st array == item in 2nd array
+  # put item in new array (the one w/ matching dudes)
+  # return new array!
+
+  list1.each do |item1| # outer loop - 1st time - item1 = 2, 2nd time - 4
+    list2.each do |item2| # inner loop - 1st time - item2 - 2, 2ndtime - item2 =3, 3rd time - item2 = 5, 4thtime, item2 - 7
+      # 2nd time we run outer loop, comparing 4 to all these guys over again - # inner loop - 1st time - item2 - 2, 2ndtime - item2 =3, 3rd time - item2 = 5, 4thtime, item2 - 7
+      if item1 == item2 # these are both integers - they are elements inside the array
+        matching_dudes << item1 # this can be item1 or item2, doesn't matter since they're the same!
+      end
+    end
+  end
+  return matching_dudes
+end
+
+list1 = [2, 4, 6, 8]
+list2 = [2, 3, 5, 7]
+puts intersection(list2, list1)
+__________________________________________________________
+QUESTION 2: 
+def permutations?(string1, string2)
+  if string1.length != string2.length
+    return false
+  end
+  hash1 = making_string_into_hash(string1)
+  hash2 = making_string_into_hash(string2)
+  if hash1 == hash2
+    return true
+  end
+  return false
+end
+
+# permutations?("hello", "ehllo") => true ["h", "e", ]
+# hello - ehllo - helo heelo oohel
+# h - 1,  e -1, l -2, o -1
+# heelo h -1 e -2 l -1, o -1
+# permutations?("pasta", "atsap") => true
+# permutations?("Pizza", "Pasta") => false
+# permutations?("", "") => true
+
+# check if the two strings have the same length
+# if the length is not ==, return false
+# if length is equal then
+# parse the two sting into key value pair
+# to do the parsing, separate the sring into char
+# count how many times the char exist and assign number
+# initialize an empty hash, {} no keys.
+# to count the char, create a loop .each_char h, e, l, l, o
+# on our first loop through, h is our character. 'h' => 1
+# if 'h' is not in the hash, we need to add it
+# if 'h' is in the hash, then we need to +1 the value
+# then compare the two hashes that are created
+
+def making_string_into_hash(string)
+  empty_hash = {}
+  string.each_char do |char|
+    # .each_char work for string...(to iterater over a string, .each will work on hash and array)
+    if empty_hash[char] # {'l' => 1}
+      empty_hash[char] += 1 # {'l' => 2}
+    else
+      empty_hash[char] = 1
+    end
+  end
+  return empty_hash
+end
+
+puts(making_string_into_hash("hello"))
+puts(making_string_into_hash("elloh"))
+__________________________________________________________
+QUESTION 3: 
+
+require_relative "permutations.rb"
+
+def palindrome_permutation?(string)
+  hash = making_string_into_hash(string)
+  number_of_time_count_is_odd = 0
+  hash.each do |letter, count|
+    number_of_time_count_is_odd += 1 if count.odd?
+    # number_of_time_count_is_odd += 1 if count % 2 == 1 (another method to use instead)
+  end
+  return number_of_time_count_is_odd <= 1
+end
+
+# create a var of hash and set it == the helper method from permutations.rb making_string_into_hash(string)
+  # (since you want to change the string into hash with key: value, ie, letter: count)
+# create (number_of_time_count_is_odd) var and set it == to 0
+# use .each method on the hash to get the number of count number
+# use if statment to see if the number count is odd or even number
+  # looking at the test, a word to be a palindrom needs:
+  # either be an even number || odd with just one nubmer example "racecar"
+# if the stored count amount == even number or has one odd number
+# return true to palindrome
+# return true to empty string
+# return false for anything else

test/array_intersection_test.rb

@@ -12,4 +12,4 @@
   it "returns [50, 25, 43] for 50, 43, 25, 72], and [25, 36, 43, 50, 80]" do
     expect(intersection([50, 43, 25, 72], [25, 36, 43, 50, 80]).sort).must_equal [25, 43, 50]
   end
-end
+end

test/palindrome_permutation_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "palindrome_permutation?" do
+describe "palindrome_permutation?" do
   it "will work for hello" do
     expect(palindrome_permutation?("hello")).must_equal false
   end
@@ -19,5 +19,9 @@
 
   it "will return false for raceca" do
     expect(palindrome_permutation?("raceca")).must_equal false
-  end   
-end
+  end
+
+  it "will return true for 'hannah'" do
+    expect(palindrome_permutation?("hannah")).must_equal true
+  end
+end

test/permutations_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "permutations?" do
+describe "permutations?" do
   it "returns true for empty string" do
     expect(permutations?("", "")).must_equal true
   end
@@ -20,4 +20,4 @@
   it "returns false if the number of a specific letter are different" do
     expect(permutations?("pizza", "piza")).must_equal false
   end
-end
+end

test/test_helper.rb

@@ -1,5 +1,5 @@
-require 'minitest/autorun'
-require 'minitest/reporters'
+require "minitest/autorun"
+require "minitest/reporters"
 require "minitest/skip_dsl"
 
 Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new