AA tree

Create an empty tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(aa-tree-empty <)

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0.

Check if a value is a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(write-u8 (if (aa-tree? (aa-tree-empty <)) 65 66))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “A”.

Find no value

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(define tree (aa-tree-empty <))

(write-u8 (if (aa-tree-find tree 1) 65 66))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “B”.

Insert a value into a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(define tree (aa-tree-empty <))

(aa-tree-insert! tree 1)

(write-u8 (if (= (aa-tree-find tree 1) 1) 65 66))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “A”.

Insert a value into a left of a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(define tree (aa-tree-empty <))

(aa-tree-insert! tree 2)
(aa-tree-insert! tree 1)

(for-each
  (lambda (x)
    (write-u8 (if (eq? (aa-tree-find tree x) x) 65 66)))
  '(1 2 3))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “AAB”.

Insert a value into a right of a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(define tree (aa-tree-empty <))

(aa-tree-insert! tree 1)
(aa-tree-insert! tree 2)

(for-each
  (lambda (x)
    (write-u8 (if (eq? (aa-tree-find tree x) x) 65 66)))
  '(1 2 3))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “AAB”.

Insert a value into the same node of a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(define tree (aa-tree-empty <))

(aa-tree-insert! tree 1)
(aa-tree-insert! tree 1)

(write-u8 (if (eq? (aa-tree-find tree 1) 1) 65 66))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “A”.

Insert values into a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(define tree (aa-tree-empty <))

(define (check x)
  (write-u8 (if (eq? (aa-tree-find tree x) x) 65 66)))

(for-each
  (lambda (x)
    (check x)
    (aa-tree-insert! tree x)
    (check x))
  '(<values>))

(for-each check '(<values>))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “<output>”.

Examples

values	output
1 2 3	BABABAAAA
1 3 2	BABABAAAA
2 1 3	BABABAAAA
2 3 1	BABABAAAA
3 1 2	BABABAAAA
3 2 1	BABABAAAA
1 2 3 4	BABABABAAAAA
1 2 4 3	BABABABAAAAA
1 3 2 4	BABABABAAAAA
1 3 4 2	BABABABAAAAA
1 4 2 3	BABABABAAAAA
1 4 3 2	BABABABAAAAA
2 1 3 4	BABABABAAAAA
2 1 4 3	BABABABAAAAA
2 3 1 4	BABABABAAAAA
2 3 4 1	BABABABAAAAA
2 4 1 3	BABABABAAAAA
2 4 3 1	BABABABAAAAA

Convert a list into a tree

Given a file named “main.scm” with:

(import (scheme base) (stak aa-tree))

(write-u8 (if (equal? (aa-tree->list (list->aa-tree '(<values>) <)) '(<output>)) 65 66))

When I run the following script:

scheme -l $STAK_ROOT/aa-tree.scm main.scm

Then the exit status should be 0

And the stdout should contain exactly “A”.

Examples

values	output
1	1
1 2	1 2
2 1	1 2
1 2 3	1 2 3
1 3 2	1 2 3
2 1 3	1 2 3
2 3 1	1 2 3
3 1 2	1 2 3
3 2 1	1 2 3
1 2 3 4	1 2 3 4
1 2 4 3	1 2 3 4
1 3 2 4	1 2 3 4
1 3 4 2	1 2 3 4
1 4 2 3	1 2 3 4
1 4 3 2	1 2 3 4
2 1 3 4	1 2 3 4
2 1 4 3	1 2 3 4
2 3 1 4	1 2 3 4
2 3 4 1	1 2 3 4
2 4 1 3	1 2 3 4
2 4 3 1	1 2 3 4