Average of levels in binary tree

Interview Question - Average of levels in binary tree Solved using a simple Breadth First Search (BFS) algorithm while keep tracking of levels.

Transcript

1. Average of Levels in Binary Tree 3 11 9 4 1 7 4 Illustration by Oussama Zaki Variables Queue Averages nodes_count_per_level = sum_per_level = node
2. Average of Levels in Binary Tree Illustration by Oussama Zaki Initializing with the root node 3 ∅ Queue Averages nodes_count_per_level = sum_per_level = node 3 11 9 4 1 7 4
3. Average of Levels in Binary Tree Illustration by Oussama Zaki Loop - Picking up a node from the Queue ∅ Queue Averages nodes_count_per_level = 1 sum_per_level = 3 3 node 3 11 9 4 1 7 4
4. Average of Levels in Binary Tree Illustration by Oussama Zaki Adding left child ∅ 11 Queue Averages nodes_count_per_level = 1 sum_per_level = 3 3 node 3 11 9 4 1 7 4
5. Average of Levels in Binary Tree Illustration by Oussama Zaki Adding right child ∅ 11 4 Queue Averages nodes_count_per_level = 1 sum_per_level = 3 3 node 3 11 9 4 1 7 4
6. Average of Levels in Binary Tree Illustration by Oussama Zaki Loop - Picking up a node from the Queue 11 4 Queue Averages nodes_count_per_level = 1 sum_per_level = 3 ∅ node 3 11 9 4 1 7 4
7. Average of Levels in Binary Tree Illustration by Oussama Zaki Null node ⟹ End of level ⟹ Update averages 11 4 Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 ∅ node 3 11 9 4 1 7 4
8. Average of Levels in Binary Tree Illustration by Oussama Zaki Null node ⟹ End of level & first node is not Null 11 4 ∅ Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 ∅ node 3 11 9 4 1 7 4
9. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue 4 ∅ Queue Averages nodes_count_per_level = 1 sum_per_level = 11 3 11 node
10. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Adding left child 4 ∅ 4 Queue Averages nodes_count_per_level = 1 sum_per_level = 11 3 11 node
11. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue ∅ 4 Queue Averages nodes_count_per_level = 1 + 1 sum_per_level = 11 + 4 3 4 node
12. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Adding left child ∅ 4 1 Queue Averages nodes_count_per_level = 1 + 1 sum_per_level = 11 + 4 3 4 node
13. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Adding right child ∅ 4 1 7 Queue Averages nodes_count_per_level = 1 + 1 sum_per_level = 11 + 4 3 4 node
14. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue 4 1 7 Queue Averages nodes_count_per_level = 1 + 1 sum_per_level = 11 + 4 3 ∅ node
15. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Null node ⟹ End of level 4 1 7 Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 ∅ node
16. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Null node ⟹ End of level & first node is not Null 4 1 7 ∅ Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 ∅ node
17. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue 1 7 ∅ Queue Averages nodes_count_per_level = 1 sum_per_level = 4 3 7.5 4 node
18. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue 7 ∅ Queue Averages nodes_count_per_level = 1 + 1 sum_per_level = 4 + 1 3 7.5 1 node
19. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue ∅ Queue Averages nodes_count_per_level = 1 + 1 + 1 sum_per_level = 4 + 1 + 7 3 7.5 7 node
20. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Adding right child ∅ 9 Queue Averages nodes_count_per_level = 1 + 1 + 1 sum_per_level = 4 + 1 + 7 3 7.5 7 node
21. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue 9 Queue Averages nodes_count_per_level = 1 + 1 + 1 sum_per_level = 4 + 1 + 7 3 7.5 ∅ node
22. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Null node ⟹ End of level 9 Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 4 ∅ node
23. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Null node ⟹ End of level & first node is not Null 9 ∅ Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 4 ∅ node
24. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue ∅ Queue Averages nodes_count_per_level = 1 sum_per_level = 9 3 7.5 4 9 node
25. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Loop - Picking up a node from the Queue Queue Averages nodes_count_per_level = 1 sum_per_level = 9 3 7.5 4 ∅ node
26. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Null node ⟹ End of level Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 4 9 ∅ node
27. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 Null node ⟹ End of level & first node is Null ∅ Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 4 9 ∅ node
28. Average of Levels in Binary Tree Illustration by Oussama Zaki 3 11 9 4 1 7 4 End ∅ Queue Averages nodes_count_per_level = 0 sum_per_level = 0 3 7.5 4 9 ∅ node