Hi,
Perhaps I didn't explain myself well.
When you solve the programming question I introduced here, how can you prove that your solution returns a permutation with 1/N! probability.
For example, consider the following solution:
Lets take for example, N=4.
The given array is 1,2,3,4.
Call rand(4), say it returns 2.
Therefore, exchange between organ #2 and organ #4.
Now, call rand(3), say it returns 1.
Therefore, exchange between organ #1 and organ #3.
Now, call rand(2)...
and so on.
How can I prove that each permutation this solution returns has 1/N! probabilty?