1 files changed, 72 insertions, 0 deletions
diff --git a/simulation_test/Question3_N24.py b/simulation_test/Question3_N24.py
new file mode 100644
index 0000000..55f20b2
--- /dev/null
+++ b/simulation_test/Question3_N24.py
@@ -0,0 +1,72 @@
+# initialise linked list structure 
+global LinkedList
+# creating empty data and joining pointers
+LinkedList = [[-1, i + 1] for i in range(0, 20)]
+# set last element to be null pointer
+LinkedList[-1][1] = -1
+global FirstEmpty
+global FirstNode
+FirstEmpty = 0
+FirstNode = -1
+
+def InsertData():
+    global FirstEmpty, FirstNode, LinkedList
+    for i in range(5):
+        number = int(input("your positive integer number: "))
+        while number < 0:
+            print("invalid, must be positive!")
+            number = int(input("your positive integer number: "))
+        if FirstEmpty != -1:
+            # the linked list is not full
+            NextEmpty = LinkedList[FirstEmpty][1]
+            LinkedList[FirstEmpty][0] = number
+            LinkedList[FirstEmpty][1] = FirstNode
+            FirstNode = FirstEmpty
+            FirstEmpty = NextEmpty
+        else:
+            return
+
+def OutputLinkedList():
+    global FirstNode, LinkedList
+    # assign initial node location
+    next_node = FirstNode
+    while next_node != -1:
+        # outputs the data at the given position
+        print(LinkedList[next_node][0])
+        # updates the next following pointer
+        next_node = LinkedList[next_node][1]
+
+InsertData()
+OutputLinkedList()
+
+def RemoveData(target_data):
+    global FirstNode, FirstEmpty, LinkedList
+    current_node = FirstNode
+    next_node = LinkedList[FirstNode][1]
+    if LinkedList[current_node][0] == target_data:
+        # the first node needs to be removed
+        new_first_node = LinkedList[current_node][1]
+        LinkedList[current_node][1] = FirstEmpty
+        FirstEmpty = current_node
+        FirstNode = new_first_node
+        return
+    while current_node != -1:
+        # checks if the immediately succeeding element is target
+        if LinkedList[next_node][0] == target_data:
+            if LinkedList[next_node][1] == -1:
+                # the target is at the end of the list
+                # terminating linked list with null pointer
+                LinkedList[current_node][1] = -1
+            # put element in empty list
+            else:
+                # the target is in the middle of the list 
+                # skip the removed element
+                LinkedList[current_node][1] = LinkedList[next_node][1]
+                LinkedList[next_node][1] = FirstEmpty
+            FirstEmpty = next_node
+            return # returning here because only matching for one occurrence
+        current_node = next_node
+        next_node = LinkedList[next_node][1]
+RemoveData(5)
+print("After")
+OutputLinkedList()
+\ No newline at end of file