The document describes the process of preorder tree traversal using a stack. It involves pushing the root node to the stack, popping nodes from the stack and visiting them while also pushing their children, and repeating until the stack is empty. This traversal results in the root node being visited first, followed by left children, and then right children.

1. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
14 84 13 53 06 99 72 43 33 64 97 51 25
14
Stack
14
43
84
16
13
53
99
33
72
97
64

2. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
84
43
14 84 13 53 06 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

3. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
13
16
43
14 84 13 53 06 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

4. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
53
16
43
14 84 13 53 06 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

5. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
16
43
14 84 13 53 06 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

6. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
99
72
43
14 84 13 53 16 99 72 43 33 64 97 51 25
Stack
14
43
84
16
6
13
53
99
33
72
97
64

7. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
72
43
14 84 13 53 16 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

8. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
14 84 13 53 16 99 72 43 33 64 97 51 25
43
Stack
14
43
84
16
13
53
99
33
72
97
64

9. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
33
97
14 84 13 53 16 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

10. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
64
97
14 84 13 53 16 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

11. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
14 84 13 53 16 99 72 43 33 64 97 51 25
97
Stack
14
43
84
16
13
53
99
33
72
97
64

12. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
14 84 13 53 16 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64

13. Preorder Traversal with a Stack
Push the root onto the stack.
While the stack is not empty
pop the stack and visit it
push its two children
14 84 13 53 16 99 72 43 33 64 97 51 25
Stack
14
43
84
16
13
53
99
33
72
97
64