Day 14 solution

This one's part 1 destroyed me. I had a very difficult time, trying 3 separate approaches, each one of which worked for most cases but eventually fell apart on the 5th sample or my actual puzzle input. I ended up reading a bunch of hints from the subreddit which eventually led me to a blog post describing this solution, which wasn't far off from what I had, but I was overcomplicating things.

Part 2 surprised me in that I expected a simple "ore available divided by ore needed for 1 fuel" would solve it, but of course the excess chemicals produced in any given reaction meant that it wasn't that simple. So this approach uses that estimate as a lower bound, since it always underestimates, and then bisects its way to the solution (starting at the lower bound and adding 1 each time took too long). I'm sure a smarter upper bound choice could lower the runtime of this by a bit, but runtime isn't bad enough right now for me to try any additional optimizations.

utilities/math.go

@@ -1,5 +1,7 @@
 package utilities
 
+import "math"
+
 func GCD[T Integer](a, b T) T {
 	if b == 0 {
 		return a
@@ -25,3 +27,23 @@ func LCM[T Integer](nums ...T) uint64 {
 func lcm[T Integer](a, b T) uint64 {
 	return uint64(a*b) / uint64(GCD(a, b))
 }
+
+func Min[T Number](nums ...T) T {
+	numNums := len(nums)
+	if numNums == 2 {
+		return T(math.Min(float64(nums[0]), float64(nums[1])))
+	}
+
+	if numNums == 0 {
+		return 0
+	}
+
+	least := nums[0]
+	for i := 1; i < numNums; i++ {
+		if nums[i] < least {
+			least = nums[i]
+		}
+	}
+
+	return least
+}