diff --git a/lib/linked_list.rb b/lib/linked_list.rb
index 501c60fb..7f105ca2 100644
--- a/lib/linked_list.rb
+++ b/lib/linked_list.rb
@@ -18,132 +18,265 @@ def initialize
 
     # method to add a new node with the specific data value in the linked list
     # insert the new node at the beginning of the linked list
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity: O(1)
+    # Space Complexity O(1)
     def add_first(value)
-      raise NotImplementedError
+      new_node = Node.new(value)
+      new_node.next = @head
+      @head = new_node
     end
 
     # method to find if the linked list contains a node with specified value
     # returns true if found, false otherwise
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity: O(n)
+    # Space Complexity: O(1)
     def search(value)
-      raise NotImplementedError
+      return false if @head.nil?
+      return true if @head.data = value
+      current = @head
+      until current.data.nil?
+        return true if current.data = value
+        current = current.next
+      end
     end
 
     # method to return the max value in the linked list
     # returns the data value and not the node
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def find_max
-      raise NotImplementedError
+      return nil if @head.nil?
+      current = @head
+      max = current.data
+      until current.nil?
+        max = current.data if current.data > max
+        current = current.next
+      end
+      return max
     end
 
     # method to return the min value in the linked list
     # returns the data value and not the node
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def find_min
-      raise NotImplementedError
+      return nil if @head.nil?
+      current = @head
+      min = current.data
+      until current.nil?
+        if current.data < min
+          min = current.data 
+        end
+        current = current.next
+      end
+      return min
     end
 
 
     # method that returns the length of the singly linked list
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def length
-      raise NotImplementedError
+      return 0 if @head.nil?
+      length = 0
+      current = @head
+      until current.nil?
+        current = current.next
+        length += 1
+      end
+      return length
+      
     end
 
     # method that returns the value at a given index in the linked list
     # index count starts at 0
     # returns nil if there are fewer nodes in the linked list than the index value
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def get_at_index(index)
-      raise NotImplementedError
+      return nil if length <= index
+      current = @head
+      count = 0
+      until current.nil?
+        return current.data if count == index
+        current = current.next
+        count += 1
+      end
     end
 
     # method to print all the values in the linked list
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def visit
-      raise NotImplementedError
+      current = @head
+      until current.nil?
+        puts current.data
+        current = current.next
+      end
     end
 
     # method to delete the first node found with specified value
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n) where n is the number of nodes
+    # Space Complexity: O(1)
     def delete(value)
-      raise NotImplementedError
+      return if @head.nil?
+      current = @head
+
+      if current.data == value
+        @head = current.next
+        return
+      end
+
+      prev = current
+      until current.nil?
+        if current.data == value
+          prev.next = current.next
+        else
+          prev = current
+        end
+        current = current.next
+      end
     end
 
     # method to reverse the singly linked list
     # note: the nodes should be moved and not just the values in the nodes
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n) where n is the number of nodes
+    # Space Complexity: O(1)
     def reverse
-      raise NotImplementedError
+      return nil if @head.nil?
+      prev = nil
+      current = @head
+      until current.nil?
+        temp = current.next
+        current.next = prev
+        prev = current
+        current = temp
+      end
+
+      @head = prev
+
     end
 
 
     ## Advanced Exercises
     # returns the value at the middle element in the singly linked list
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def find_middle_value
-      raise NotImplementedError
+      return nil if @head.nil?
+      current = @head
+      if length % 2 == 0
+        return nil
+      else
+        middle_index = length / 2
+      end
+      index = 0
+      until current.nil?
+        return current.data if index == middle_index
+        current = current.next
+        index += 1
+      end
+
     end
 
     # find the nth node from the end and return its value
     # assume indexing starts at 0 while counting to n
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def find_nth_from_end(n)
-      raise NotImplementedError
+      return nil if @head.nil?
+      current = @head
+      index = 0
+      until current.nil?
+        if index == length - n - 1
+          return current.data
+        end
+        index += 1
+        current = current.next
+      end
     end
 
     # checks if the linked list has a cycle. A cycle exists if any node in the
     # linked list links to a node already visited.
     # returns true if a cycle is found, false otherwise.
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def has_cycle
-      raise NotImplementedError
+      return nil if @head.nil?
+      slow_p = @head
+      fast_p = @head
+      while slow_p != nil && fast_p != nil and fast_p.next != nil
+        slow_p = slow_p.next
+        fast_p = fast_p.next.next
+        if slow_p == fast_p
+          return true
+        end
+        return false
+      end
     end
 
 
     # Additional Exercises 
     # returns the value in the first node
     # returns nil if the list is empty
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity: O(1)
+    # Space Complexity: O(1)
     def get_first
-      raise NotImplementedError
+      return nil if @head.nil?
+      return @head.data
     end
 
     # method that inserts a given value as a new last node in the linked list
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n) where n is the number of nodes
+    # Space Complexity: O(1)
     def add_last(value)
-      raise NotImplementedError
+      new_node = Node.new(value)
+      if @head.nil?
+        @head = new_node
+        return
+      end
+      current = @head
+      until current.next.nil?
+        current = current.next
+      end
+      current.next = new_node
+      
     end
 
     # method that returns the value of the last node in the linked list
     # returns nil if the linked list is empty
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n) where n is the number of nodes
+    # Space Complexity: O(1)
     def get_last
-      raise NotImplementedError
+      return nil if @head.nil?
+      current = @head
+      until current.next.nil?
+        current = current.next
+      end
+      return current.data
     end
 
     # method to insert a new node with specific data value, assuming the linked
     # list is sorted in ascending order
-    # Time Complexity:  
-    # Space Complexity
+    # Time Complexity:  O(n)
+    # Space Complexity: O(1)
     def insert_ascending(value)
-      raise NotImplementedError
+      new_node = Node.new(value)
+      @head = new_node if @head.nil?
+      current = @head
+      if current.data > new_node.data
+        temp = @head
+        @head = new_node
+        new_node.next = temp
+      end
+      until current.nil?
+        if current.data <= value && current.next.data > value
+          temp = current.next
+          current.next = new_node
+          new_node.next = temp
+        end
+        current = current.next
+      end
     end
 
     # Helper method for tests