Binary Tree Racket

bt.rkt

#lang racket


(define (create-bt line) 
    (match line
        [`(,x0 ,x1) (if (< x0 x1) `(bt ,x0 empty (bt ,x1 covered empty)) 'empty)]
        [_ 'error]
    )
)

(define (insert-bt bt line)
    (match line
        [`(,x0 ,x1)
            (match bt
                ['covered 'covered]
                ['empty (create-bt line)]
                [`(bt ,root ,left ,right)
                    `(bt ,root ,(insert-bt left `(,(min root x0) ,(min root x1))) ,(insert-bt right `(,(max root x0) ,(max root x1))))
                ]
                [_ bt]
            )
        ]
    )
)

(define (traverse-bt bt [x0 'init] [x1 'init])
    (match bt
        ['empty 0]
        ['covered (- x1 x0)]
        [`(bt ,root ,left ,right) (+ (traverse-bt left x0 root) (traverse-bt right root x1))]
        [_ 0]
    )
)

(create-bt `(6 9))
(define bts (insert-bt (create-bt `(6 9)) `(1 10)))
(traverse-bt (insert-bt bts `(3 4)))