1. import random
2. ArrayNodes = [[-1,-1,-1] for i in range(20)]
3.  
4. for i in range(19):
5.     ArrayNodes[i][0]=i+1
6.  
7. print(ArrayNodes)
8. #you should link all the nodes that are in the free list
9. RootPointer = -1
10. FreeNode = 0
11. #you should use the global variables rootpointer and freeNode, along with arrayNodes
12. #usualy, when making an AddNode function, the parameter should be the element that you want to add.
13. def AddNode(NodeData):
14.     global RootPointer, FreeNode,ArrayNodes
15.     if FreeNode <= 19:
16.         ArrayNodes[FreeNode][0] = -1
17.         ArrayNodes[FreeNode][1] = NodeData
18.         ArrayNodes[FreeNode][2] = -1
19.         if RootPointer == -1:
20.             RootPointer = 0
21.             FreeNode = 1
22.             print(ArrayNodes, flush=True)
23.         else:
24.             Placed = False
25.             CurrentNode = RootPointer
26.             print(CurrentNode,flush=True)      
27.             while Placed == False:
28.                 if NodeData < ArrayNodes[CurrentNode][1]:
29.                     if ArrayNodes[CurrentNode][0] == -1:
30.                         ArrayNodes[CurrentNode][0] = FreeNode
31.                         Placed = True
32.                     else:
33.                         CurrentNode = ArrayNodes[CurrentNode][0]
34.                 elif ArrayNodes[CurrentNode][2] == -1:
35.                     ArrayNodes[CurrentNode][2] = FreeNode
36.                     Placed = True
37.                 else:
38.                     CurrentNode = ArrayNodes[CurrentNode][2]
39.  
40.             FreeNode = FreeNode + 1
41.     else:
42.         print("Tree is full")
43.  
44. def PrintAll(ArrayNodes):
45.     for i in range(5):
46.         print(ArrayNodes[i][0], ArrayNodes[i][1], ArrayNodes[i][2])
47.  
48. AddNode(90)
49. AddNode(80)
50. AddNode(172)
51. AddNode(34)
52. AddNode(10)
53. print(RootPointer)
54. PrintAll(ArrayNodes)