How could I take multiple outputs and output the leftmost output?

Solution 1:

Here it is the system:

And here it is, missing one layer:

I made it so you could loop it and repeat as many times you want. Dark blocks need to not be a transparent block (such as glass or slabs) and need to be there (cannot be missing), light ones can be either and quartz do not matter. There is nothing under the torches that are close to the Lamps.

Basically it's a chain reaction. Because of how repeaters work (Input can only come from one side and output leaves from another point). you came make that the far left turn off all the torches to his right. making them 'unusable'. It would be way easier to make it with commands but I wanted to make survival friendly. If the system looks confusing in any way, I'll gladly post more screenshots. Hope it helps!.

Solution 2:

I found a much simpler answer. The mechanism involves using redstone signal strength.

People call it a Redcoder. I can't really explain it, so I'll let this guy do it:

I think he does a pretty good job saying what it's used for and how it works. Here is a picture of the different layers of the mechanism.

Thanks for everyone's solutions. I used Bruno Rodrigues in the project I was making.