Done :)

day_5/Main.gd

@@ -20,6 +20,8 @@ func read_map(lines, i):
 		entry.dst_start = int(map_entry_string[0])
 		entry.src_start = int(map_entry_string[1])
 		entry.range = int(map_entry_string[2])
+		entry.dst_end = entry.dst_start + entry.range - 1
+		entry.src_end = entry.src_start + entry.range - 1
 		
 		map.append(entry)
 			
@@ -104,90 +106,81 @@ func _on_part1():
 		
 	print("Closest location: " + str(overall_closest))
 	
-func _smallest_dst(a, b):
-	return a.dst_start < b.dst_start
+func remap_range(map, initial_range):
+	var unchopped = [initial_range]
+	var chopped = []
 	
-func _find_ranges(map, range):
-	# Determine what input ranges can yeild the given input range
-	var ranges = []
+	for i in range(len(map)):
+		var remap = map[i]
 		
-	# Sort dest ranges from lowest->higest since thats what we care about
-	var entries = map.duplicate()
-	entries.sort_custom(_smallest_dst)
+		var new_ranges = []
+		for range_ in unchopped:
+			if not (range_.start <= remap.src_end and remap.src_start <= range_.end):
+				new_ranges.append(range_)
+				continue
 		
-	# Define search range
-	# This will get bumped to the right as each new range is found
-	var search_range_start = range.src_start
-	var search_range_len = range.range
+			# Case 1
+			if range_.start < remap.src_start:
+				var range = SeedRange.new()
+				range.start = range_.start
+				range.end = remap.src_start - 1
+				new_ranges.append(range)
 				
-	for entry in map:
-		#print('Trying entry')
-		#print(entry)
-		#print('Range is')
-		#print(range)
+			# Case 2
+			var bump = remap.dst_start - remap.src_start
+			var range = SeedRange.new()
+			range.start = max(range_.start, remap.src_start) + bump
+			range.end = min(range_.end, remap.src_end) + bump
+			chopped.append(range)
 			
-		# Input range is before entry, shift it to where the entry starts
-		var nd_start = entry.dst_start - search_range_start
-		if entry.dst_start > search_range_start and nd_start < search_range_len:
-			search_range_start += nd_start
-			search_range_len -= nd_start
-			#print("Range was before entry. New range is")
-			#print(str(search_range_start) + " (" + str(search_range_len) + ")")
-			#print(entry)
+			# Case 3
+			if range_.end > remap.src_end:
+				range = SeedRange.new()
+				range.start = remap.src_end + 1
+				range.end = range_.end
+				new_ranges.append(range)
 		
-		var d_start = search_range_start - entry.dst_start
-		# Search range is contained within entry
-		if entry.dst_start <= search_range_start and d_start < entry.range:
-			var new_entry = MapEntry.new()
-			# New range's destination is the start of the search range
-			# This was given
-			new_entry.dst_start = search_range_start
-			# New range's source is the reverse apply of this mapentry
-			new_entry.src_start = entry.apply_rev(search_range_start)
-			# New range's range is either the end of the search range
-			# or the end of entry, whichever is less
-			new_entry.range = min(entry.range - d_start, search_range_len)
-			ranges.append(new_entry)
+		unchopped = Array(new_ranges)
 		
-			# Bump search range past this new entry
-			search_range_start += new_entry.range
-			search_range_len -= new_entry.range
+	return unchopped + chopped
 	
-	if len(ranges) == 0:
-		ranges.append(range)
+func do_thing(in_ranges, map):
+	var out_ranges = []
+	for seed in in_ranges:
+		var remapped = remap_range(map, seed)
+		out_ranges += remapped
 	
-	return ranges
+	return out_ranges
 
 func _on_part2():
 	var input = $TextEdit.text + '\n'  # Safety newline :)
 	var seeds_maps = parse_input(input)
-	var seeds = seeds_maps[0]
+	var seed_ints = seeds_maps[0]
 	var maps = seeds_maps[1]
 	
+	var seeds = []
+	for i in range(len(seed_ints) / 2):
+		var start = seed_ints[i * 2 + 0]
+		var length = seed_ints[i * 2 + 1]
+		
+		var seed = SeedRange.new()
+		seed.start = start
+		seed.end = start + length - 1
+		seeds.append(seed)
 	print(seeds)
-	print(maps)
 	
-	# Sort by closest locations
-	var closest_locs = maps.seed2soil.duplicate()
-	closest_locs.sort_custom(_smallest_dst)
+	var soils = do_thing(seeds, maps.seed2soil)
+	var fertilizers = do_thing(soils, maps.soil2fertilizer)
+	var waters = do_thing(fertilizers, maps.fertilizer2water)
+	var lights = do_thing(waters, maps.water2light)
+	var temperatures = do_thing(lights, maps.light2temperature)
+	var humidities = do_thing(temperatures, maps.temperature2humidity)
+	var locations = do_thing(humidities, maps.humidity2location)
 	
-	print('Closest Humidities')
-	print(closest_locs)
+	print(locations)
 	
-	# for loc in closest_locs:
-	var light_ranges = _find_ranges(maps.light2temperature, closest_locs[1])
-	print('Light ranges')
-	print(light_ranges)
-	var water_ranges = _find_ranges(maps.water2light, light_ranges[0])
-	print('Water ranges')
-	print(water_ranges)
+	var lowest = locations[0].start
+	for loc in locations:
+		lowest = min(lowest, loc.start)
 	
-	var search_maps = [
-		maps.humidity2location,
-		maps.temperature2humidity,
-		maps.light2temperature,
-		maps.water2light,
-		maps.fertilizer2water,
-		maps.soil2fertilizer,
-		maps.seed2soil
-	]
+	print(lowest)

day_5/MapEntry.gd

@@ -2,6 +2,8 @@ class_name MapEntry
 
 var src_start := 0
 var dst_start := 0
+var src_end := 0
+var dst_end := 0
 var range := 0
 
 func _to_string():

day_5/SeedRange.gd

@@ -0,0 +1,7 @@
+class_name SeedRange
+
+var start := 0
+var end := 0
+
+func _to_string():
+	return str(self.start) + " -> " + str(self.end)