HtDP Problem Set
Develop the function between?, which consumes three numbers and produces
trueif the last is between the first two, otherwise it returns
Use between? to develop the function three-between?, which consumes two numbers and a list of three numbers and determines if all three numbers in the list are between the first two.
Develop a function that consumes a list of booleans and determines whether one of them is
true. Consider whether
Develop a function that consumes a list of numbers and computes the difference between the number of positive numbers in the list and the number of negative numbers in the list.
Develop the function string-append-n*, which consumes a non-empty list of strings and produces a single string resulting from appending all of the strings together. Use the built-in function string-append:
String String -> String, which appends two strings.
Now develop the more general function string-append*, which consumes any list of strings and produces a single string as described above. This new function must handle empty in reasonable way.
Develop the function order-toy, which consumes a symbol representing a toy, a number representing how many of that particular toy you wish to have in stock, and a list of symbols representing an inventory of toys. It produces the number copies that need to be ordered. Consider using the how-many-symbols function from Exercise 9.5.2 as a helper.
|Jamie Raymond||Matthias Felleisen|
23 september 2002