Suppose you want to make a random 9 digit number, using every number from 1 to 9 exactly once. You have a process called random(top) that gives a random number up to top (if top was 5, it would give random numbers from 1 to 5)

a) How could you do this?

b) If top couldn't be more than 9, how could you do this using random(top) only 9 times (or less)?

(In reply to solution by Charlie)

Note that in the Basic computer language of my solution, strings are variable length, so as the letters are extracted from the source string, the string's total length decreases, with no padding with blanks. Also I meant to say "length 9" for the original length of the source string.

Posted by Charlie on 2003-05-02 08:20:59