2020 days 1 and 2

2020/day01.py

@@ -0,0 +1,18 @@
+with open('input01', 'r') as file:
+  data = sorted([int(i) for i in file.readlines()])
+
+def find_pair_sum(total, data):
+  for x in data:
+    y = total - x
+    if y in data:
+      return x, y
+  return None, None
+
+x, y = find_pair_sum(2020, data)
+print(f'Part 1: {x}*{y} = {x*y}')
+
+for idx, x in enumerate(data):
+  y, z = find_pair_sum(2020-x, data[idx+1:])
+  if y:
+    print(f'Part 2: {x}*{y}*{z} = {x*y*z}')
+    break

2020/day02.py

@@ -0,0 +1,10 @@
+import re
+ex = re.compile(r'(\d+)-(\d+) (\w): (.*)')
+with open('input02', 'r') as file:
+  data = [ex.match(line).groups() for line in file.readlines()]
+
+valid = [(int(i)<=s.count(c)<=int(j)) for i,j,c,s in data]
+print(f'Part 1: {valid.count(True)}')
+
+valid2 = [(s[int(i)-1]==c)^(s[int(j)-1]==c) for i,j,c,s in data]  # This is fragile, beware inputs that may have indices out of range!
+print(f'Part 2: {valid2.count(True)}')

2020/input01

@@ -0,0 +1,200 @@
+1472
+1757
+1404
+1663
+1365
+1974
+1649
+1489
+1795
+1821
+1858
+1941
+1943
+1634
+1485
+1838
+817
+1815
+1442
+639
+1182
+1632
+1587
+1918
+1040
+1441
+1784
+1725
+1951
+1285
+285
+1224
+1755
+1748
+1488
+1374
+1946
+1771
+1809
+1929
+1621
+1462
+2001
+1588
+1888
+1959
+1787
+1690
+1363
+1567
+1853
+1990
+1819
+1904
+1458
+1882
+1348
+1957
+1454
+1557
+1471
+332
+1805
+1826
+1745
+1154
+1423
+1852
+1751
+1194
+1430
+1849
+1962
+1577
+1470
+1509
+1673
+1883
+1479
+1487
+2007
+1555
+1504
+1570
+2004
+978
+1681
+1631
+1791
+1267
+1245
+1383
+1482
+1355
+1792
+1806
+1376
+1199
+1391
+1759
+1474
+1268
+1942
+1936
+1766
+1233
+1876
+1674
+1761
+1542
+1468
+1543
+1986
+2005
+1689
+1606
+1865
+1783
+1807
+1779
+1860
+1408
+1505
+1435
+1205
+1952
+1201
+1714
+1743
+1872
+1897
+1978
+1683
+1846
+858
+1528
+1629
+1510
+1446
+1869
+1347
+685
+1478
+1387
+687
+1964
+1968
+1429
+1460
+1777
+1417
+1768
+1672
+1767
+1400
+1914
+1715
+1425
+1700
+1756
+1835
+1926
+1889
+1568
+1393
+1960
+1540
+1810
+1401
+1685
+830
+1789
+1652
+1899
+796
+1483
+1261
+1398
+1727
+1566
+1812
+1937
+1993
+1286
+1992
+1611
+1825
+1868
+1870
+1746
+1361
+1418
+1820
+1598
+1911
+1428
+1734
+1833
+1436
+1560