Random character generator algorithm
Will someone please critique my algorithm/plan?
I need to write a program that will generate random characters (they can be either numbers, or upper or lower case letters) in the following format u328-iK23-o32k-A28j.
My plan is to get a clock() reading after the user has entered a prompt, and use that to generate a random character. After the first and every subsequent random character is generated, I plan to use the clock at that point in the program to generate another one. Is this legitimate? Any comments, suggestions, or recommendations?
Note: I need to do this without using any of the random number functions