Question $5$

; Input contract: n is a nonnegative integer, L is a list $($possibly empty$)$

; Output contract: $($dropLast n L$)$ is the list L with the last n elements removed $($if you try to drop more elements than

; actually exist in L$,$ then everything will be gone and so the empty list would be returned$)$

; Example: $($dropLast $3\text{'}($a b c d e f g$))$ would be $\text{'}($a b c d$)$ since the last three elements $($the e$,$f$,$g$)$ were dropped.

; Requirements: do NOT use "let" or "list$-$ref" or "length", instead use recursion

; Hint: writing the appropriate helper function will make this problem much easier.

$($define $($dropLast n L$))$

Below are the tests that need to pass:

;Test Bed

$($display "Question $5$ Tests

$")$

$($define$-$test$-$suite test$\_$sum$5$

$($test$-$equal? $""($dropLast $0\text{'}($a b c d e f g h$))\text{'}($a b c d e f g h$))$

$($test$-$equal? $""($dropLast $1\text{'}($a b c d e f g h$))\text{'}($a b c d e f g$))$

$($test$-$equal? $""($dropLast $2\text{'}($a b c d e f g h$))\text{'}($a b c d e f$))$

$($test$-$equal? $""($dropLast $3\text{'}($a b c d e f g h$))\text{'}($a b c d e$))$

$($test$-$equal? $""($dropLast $4\text{'}($a b c d e f g h$))\text{'}($a b c d$))$

$($test$-$equal? $""($dropLast $5\text{'}($a b c d e f g h$))\text{'}($a b c$))$

$($test$-$equal? $""($dropLast $6\text{'}($a b c d e f g h$))\text{'}($a b$))$

$($test$-$equal? $""($dropLast $7\text{'}($a b c d e f g h$))\text{'}($a$))$

$($test$-$equal? $""($dropLast $8\text{'}($a b c d e f g h$))$ null$)$

$($test$-$equal? $""($dropLast $9\text{'}($a b c d e f g h$))$ null$))$

$($define q$5\_$score $(-10($run$-$tests test$\_$sum$5$ 'verbose$)))$

#$|$