Merge pull request #62 from TheAlgorithms/feature/unify-folder-name

Unify the folder name

DIRECTORY.md

@@ -8,9 +8,9 @@
     * [Invert](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/binary_trees/invert.rb)
     * [Postorder Traversal](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/binary_trees/postorder_traversal.rb)
     * [Preorder Traversal](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/binary_trees/preorder_traversal.rb)
-  * Linkedlists
-    * [Double List](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/LinkedLists/double_list.rb)
-    * [Single List](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/LinkedLists/single_list.rb)
+  * Linked Lists
+    * [Double List](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/linked_lists/double_list.rb)
+    * [Single List](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/linked_lists/single_list.rb)
 
 ## Discrete Mathematics
   * [Euclidean Gcd](https://github.com/TheAlgorithms/Ruby/blob/master/discrete_mathematics/euclidean_gcd.rb)
@@ -21,33 +21,33 @@
 
 ## Project Euler
   * Problem 1
-    * [Problem1 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%201/problem1_sol1.rb)
+    * [Problem1 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_1/problem1_sol1.rb)
   * Problem 2
-    * [Problem2 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%202/problem2_sol1.rb)
+    * [Problem2 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_2/problem2_sol1.rb)
   * Problem 20
-    * [Problem20 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%2020/problem20_sol1.rb)
+    * [Problem20 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_20/problem20_sol1.rb)
   * Problem 21
-    * [Problem21 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%2021/problem21_sol1.rb)
+    * [Problem21 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_21/problem21_sol1.rb)
   * Problem 22
-    * [Problem22 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%2022/problem22_sol1.rb)
+    * [Problem22 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_22/problem22_sol1.rb)
   * Problem 3
-    * [Problem3 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%203/problem3_sol1.rb)
+    * [Problem3 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_3/problem3_sol1.rb)
   * Problem 5
-    * [Problem5 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/Project%20Euler/Problem%205/problem5_sol1.rb)
+    * [Problem5 Sol1](https://github.com/TheAlgorithms/Ruby/blob/master/project_euler/problem_5/problem5_sol1.rb)
 
 ## Searches
-  * [Binary Search](https://github.com/TheAlgorithms/Ruby/blob/master/Searches/binary_search.rb)
-  * [Depth First Search](https://github.com/TheAlgorithms/Ruby/blob/master/Searches/depth_first_search.rb)
-  * [Linear Search](https://github.com/TheAlgorithms/Ruby/blob/master/Searches/linear_search.rb)
+  * [Binary Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/binary_search.rb)
+  * [Depth First Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/depth_first_search.rb)
+  * [Linear Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/linear_search.rb)
 
 ## Sorting
-  * [Bogo Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/bogo_sort.rb)
-  * [Bubble Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/bubble_sort.rb)
-  * [Bucket Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/bucket_sort.rb)
-  * [Heap Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/heap_sort.rb)
-  * [Insertion Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/insertion_sort.rb)
-  * [Merge Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/merge_sort.rb)
-  * [Quicksort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/quicksort.rb)
-  * [Radix Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/radix_sort.rb)
-  * [Selection Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/selection_sort.rb)
-  * [Shell Sort](https://github.com/TheAlgorithms/Ruby/blob/master/Sorting/shell_sort.rb)
+  * [Bogo Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/bogo_sort.rb)
+  * [Bubble Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/bubble_sort.rb)
+  * [Bucket Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/bucket_sort.rb)
+  * [Heap Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/heap_sort.rb)
+  * [Insertion Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/insertion_sort.rb)
+  * [Merge Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/merge_sort.rb)
+  * [Quicksort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/quicksort.rb)
+  * [Radix Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/radix_sort.rb)
+  * [Selection Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/selection_sort.rb)
+  * [Shell Sort](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/shell_sort.rb)