linked list - progress update

README.md

@@ -662,10 +662,9 @@ if you can identify the runtime complexity of different algorithms. It's a super
         - [x] front() - get value of front item
         - [x] back() - get value of end item
         - [x] insert(index, value) - insert value at index, so current item at that index is pointed to by new item at index
-        - [ ] erase(index) - removes node at given index
-        - [ ] value_n_from_end(n) - returns the value of the node at nth position from the end of the list
+        - [x] erase(index) - removes node at given index
         - [x] reverse() - reverses the list
-        - [ ] remove_value(value) - removes the first item in the list with this value
+        - [x] remove_value(value) - removes the first item in the list with this value
     - [ ] Doubly-linked List
         - [Description (video)](https://www.coursera.org/lecture/data-structures/doubly-linked-lists-jpGKD)
         - No need to implement

learn_python/implementig_linked_list/models/linked_list.py

@@ -97,14 +97,11 @@ class LinkedList:
         if index == 0:
             self.push_front(value)
             return
-        if self.size() == 1 and index == 1:
-            self.push_back(value)
-            return
         else:
             cur_index = 0
             node = self.__head
             prev = node
-            while cur_index != index and node.get_next() is not None:
+            while cur_index != index and node is not None:
                 cur_index += 1
                 prev = node
                 node = node.get_next()
@@ -145,6 +142,35 @@ class LinkedList:
                 node = node.get_next()
             self.__head = reversed_list.__head
 
+    def remove_at(self, index):
+        if index > self.size() or index < 0:
+            raise IndexError(index)
+        node = self.__head
+        prev = node
+        cur_index = 0
+        while cur_index != index:
+            if node.get_next() is not None:
+                prev = node
+                node = node.get_next()
+                cur_index += 1
+            else:
+                break
+        if cur_index == index:
+            prev.set_next(node.get_next())
+        else:
+            raise IndexError(index)
+
+    def remove_value(self, value):
+        node = self.__head
+        prev = node
+        while node.get_next() is not None:
+            if node.get_value() == value:
+                prev.set_next(node.get_next())
+                break
+            else:
+                prev = node
+                node = node.get_next()
+
     def print(self):
         str = ""
         node = self.__head

learn_python/implementig_linked_list/tests/linked_list_tests.py

@@ -88,6 +88,30 @@ class LinkedListTestCase(unittest.TestCase):
         printed = linked_list.print()
         self.assertEqual(output, printed)
 
+    def test_remove_at(self):
+        linked_list = LinkedList()
+        linked_list.push_back(0)
+        linked_list.push_back(1)
+        linked_list.push_back(2)
+        linked_list.push_back(3)
+
+        linked_list.remove_at(2)
+        output = "0 1 3"
+        printed = linked_list.print()
+        self.assertEqual(output, printed)
+
+    def test_remove_value(self):
+        linked_list = LinkedList()
+        linked_list.push_back(0)
+        linked_list.push_back(1)
+        linked_list.push_back(2)
+        linked_list.push_back(10)
+        linked_list.push_back(3)
+
+        linked_list.remove_value(10)
+        output = "0 1 2 3"
+        printed = linked_list.print()
+        self.assertEqual(output, printed)
 
 
 if __name__ == '__main__':