1 files changed, 101 insertions, 0 deletions
diff --git a/05/main.py b/05/main.py
new file mode 100755
index 0000000..c947ab7
--- /dev/null
+++ b/05/main.py
@@ -0,0 +1,101 @@
+#!/bin/python3
+import sys
+import re
+
+# i want to throw up
+
+numbers = [int(x) for x in input().split(":")[1].split()]
+seed_ranges = []
+for x in range(0, len(numbers), 2):
+  seed_ranges.append((numbers[x], numbers[x] + numbers[x+1],))
+
+STEPS = [
+  'seed',
+  'soil',
+  'fertilizer',
+  'water',
+  'light',
+  'temperature',
+  'humidity',
+  'location',
+]
+
+maps = []
+current_map = {"from": "", "to": ""}
+for line in sys.stdin:
+  line = line.strip()
+  if len(line) == 0: continue
+
+  if "map:" in line:
+    current_map["from"], current_map["to"] = line.split()[0].split("-to-")
+  else:
+    dest_start, source_start, range_len = [int(x) for x in line.split()]
+    current_map["src_range"] = (source_start, source_start + range_len,)
+    current_map["dest_range"] = (dest_start, dest_start + range_len,)
+    current_map["offset"] = dest_start - source_start
+    current_map["length"] = range_len
+    maps.append(dict(current_map))
+
+output_ranges = []
+for inital_range in seed_ranges:
+  ranges = [inital_range]
+  # print(f"------ NEXT INPUT RANGE SET: {ranges} -------")
+  for step in STEPS[:-1]:
+    # print(f"[{step}] {len(ranges)} input ranges: {ranges}")
+    current_step_maps = [m for m in maps if m["from"] == step]
+    # print(f"current_step_maps\n\t" + '\n\t'.join([str(d) for d in current_step_maps]))
+    next_ranges = set()
+    for range in ranges:
+      applicable_maps = [m for m in current_step_maps if \
+                            m["src_range"][0] <= range[0] < m["src_range"][1] or \
+                            m["src_range"][0] < range[1] <= m["src_range"][1]]
+      applicable_maps = sorted(applicable_maps, key=lambda d: d["src_range"][0])
+      index = range[0]
+      # print(f"map range {range} using maps\n\t" + '\n\t'.join([str(d) for d in applicable_maps]))
+      while index < range[1]:
+        cover_step = 0
+        offset = 0
+        if len(applicable_maps) == 0:
+          # print("> no more maps ahead!")
+          cover_step = range[1] - index
+          offset = 0
+        else:
+          next_map = applicable_maps[0]
+          if next_map["src_range"][0] <= index < next_map["src_range"][1]:
+            # print(f"> {index} in map range")
+            cover_step = next_map["src_range"][1] - index
+            offset = next_map["offset"]
+            applicable_maps.pop(0)
+          else:
+            # print("> skipping until next map")
+            cover_step = next_map["src_range"][0] - index
+            offset = 0
+
+        cover_step = min(cover_step, range[1] - index)
+        next_ranges.add((index + offset, index + cover_step + offset,))
+
+        # print(f"  creating a range with length {cover_step} and offset {offset}:")
+        # print(f"    {(index, index + cover_step,)} -> {(index + offset, index + cover_step + offset,)}")
+
+        index += cover_step
+      # print(f"> end of input range reached")
+    # print("\n")
+    ranges = sorted(list(next_ranges), key=lambda t: t[0])
+  output_ranges += ranges
+
+seed_ranges = sorted(seed_ranges, key=lambda t: t[0])
+output_ranges = sorted(output_ranges, key=lambda t: t[0])
+for range in seed_ranges:
+  intersections = [m for m in output_ranges if \
+      range[0] <= m[0] < range[1] or\
+      range[0] < m[1] <= range[1]]
+  if len(intersections) == 0: continue
+  intersections = [
+    (max(m[0], range[0]),
+     min(m[1], range[1]),) for m in intersections
+  ]
+  intersections = sorted(intersections, key=lambda t: t[0])
+
+  print(f">> {intersections[0][0]}")
+  break
+