[LANGUAGE: C++]

code

Part 1

I made a map of filters, where each filter had a name, and a vector of instructions. Each instruction was a tuple<char,char,int,string>. First char was the part value we were using. second char is the < or >. int the number we're comparing the part value to. string being what we do with the part if this instruction is true.

Then I made a queue of parts, all starting at the "in" filter. After a part runs thru a filter, accept/reject or pass to next filter, adding it back into the queue.

Part 2

Dealing with ranges now, the part queue is now a rangeQueue with one initial partRange all values set 1-4000. Use the same filters from part 1.

There's basically 3 things we need to care about when filtering a range. If the range is fully inside the filter, partially, or not at all.

If it's fully inside, we just accept/reject/pass to next filter the whole range.

If it's partially inside, we split the range at the compare value into 2 ranges. Accept/reject/pass the range that's inside the compare. Put the range that's outside the compare back into the queue with the same filter.

If the range is outside the compare completely, move onto the next instruction in the filter.

If we get to the last instruction in a filter, accept/reject/pass to next filter the range.

Upon accepting a range, we multiply the range values and add to total.

One thing I want to change is part 2 is a bit hard coded. Could be 1/4th as long.

​

Runs about 80ms for both parts on my computer.