# Interesting Program Problem

Hi how are you doing?
I was doing some practising on VB and came up on a problem. Now if I have 20 numbers numbered 1 to 20. And I would like to make security codes for some personnel. (hypothetically) The codes consist of 4 numbers. How would I write the program to find all the combinations of those 20 numbers. For example one of the combinations obviously will be 1234 how can I write a program to find ALL the combinations of those 20 numbers in groups of four? I would really appreciate it if you could help me out on this.

• I don't do VB, but it can be done with a recursive FOR loop...I think they are for...next loops in BASIC...Basically (this probably won't compile)...you would need to do something like this:

for number1 = 0, number1 <= 20, number1 = number1 + 1
for number2 = 0, number2 <= 20, number2 = number2 + 1
for number3 = 0, number3 <= 20, number3 = number3 + 1
for number4 = 0, number4 <= 20, number4 = number4 + 1
....what you want to post or try with here....
next number4
next number3
next number2
next number1
as such you are trying all possible numbers that can happen from 0-0-0-0 up to 20-20-20-20.

Hope this helps you some....read up on how to do a for next loop in VB...it will help...

Travis Ferguson