Solve 2016 day 20.

2016/d20.py

@@ -0,0 +1,48 @@
+def part_1(data):
+    ranges = []
+    for line in data.splitlines():
+        l, h = list(map(int, line.split("-")))
+        ranges.append((l, h))
+
+    ranges.sort()
+    merged = list(ranges[0])
+    for i in range(1, len(ranges)):
+        current = ranges[i]
+        if current[0] <= merged[1] + 1:
+            merged[1] = max(current[1], merged[1])
+        else:
+            print(merged[1] + 1)
+            return
+
+
+def part_2(data):
+    ranges = []
+    for line in data.splitlines():
+        l, h = list(map(int, line.strip().split("-")))
+        ranges.append((l, h))
+
+    ranges.sort()
+    blocked_merged = [list(ranges[0])]
+    for block in ranges:
+        merged = blocked_merged[-1]
+        if block[0] <= merged[1] + 1:
+            merged[1] = max(block[1], merged[1])
+        else:
+            blocked_merged.append(list(block))
+
+    total = 2**32
+    for lo, hi in blocked_merged:
+        total -= (hi - lo + 1)
+    print(total)
+
+
+def main():
+    data = open(0).read().strip()
+    part_1(data)
+    part_2(data)
+
+
+if __name__ == "__main__":
+    main()
+
+

README.md

@@ -52,7 +52,8 @@ written in Python.
 - Day 17: 45:00 didn't follow instructions... focus!
 - Day 18: 9:43
 - Day 19: 90:00 that wasn't easy for me
-- Day 20: 
+- Day 20: 67:00
+- Day 21:
 
 
 # 2017