solve 3_linked_list first excercise

Author: KamilMarzynski

data_structures/3_LinkedList/3_linked_list.py

@@ -85,15 +85,42 @@ def insert_values(self, data_list):
         for data in data_list:
             self.insert_at_end(data)
 
+    def insert_after_value(self, data_after, data_to_insert):
+        itr = self.head
+        while itr:
+            if itr.data == data_after:
+                new_node = Node(data_to_insert, itr.next)
+                itr.next = new_node
+                break
+            itr = itr.next
+
+    def remove_by_value(self, data):
+        itr = self.head
+        prev = None
+        while itr:
+            if itr.data == data:
+                if prev:
+                    prev.next = itr.next
+                    break
+                else:
+                    self.head = itr.next
+
+            prev = itr
+            itr = itr.next
 
 if __name__ == '__main__':
     ll = LinkedList()
     ll.insert_values(["banana","mango","grapes","orange"])
-    ll.insert_at(1,"blueberry")
-    ll.remove_at(2)
     ll.print()
-
-    ll.insert_values([45,7,12,567,99])
-    ll.insert_at_end(67)
+    ll.insert_after_value("mango","apple") # insert apple after mango
+    ll.print()
+    ll.remove_by_value("orange") # remove orange from linked list
+    ll.print()
+    ll.remove_by_value("figs")
+    ll.print()
+    ll.remove_by_value("banana")
+    ll.remove_by_value("mango")
+    ll.remove_by_value("apple")
+    ll.remove_by_value("grapes")
     ll.print()