readme

day02/part2.py

@@ -0,0 +1,82 @@
+from __future__ import annotations
+
+import argparse
+import os.path
+
+import pytest
+
+import support
+
+INPUT_TXT = os.path.join(os.path.dirname(__file__), 'input.txt')
+
+
+def compute(s: str) -> int:
+    """
+    A for Rock, B for Paper, and C for Scissors. The second column--" Suddenly, the Elf is called away to help with someone's tent.
+
+    The second column, you reason, must be what you should play in response: X for Rock, Y for Paper, and Z for Scissors.
+
+    The score for a single round is the score for the shape you selected (1 for Rock, 2 for Paper, and 3 for Scissors) plus the score for the outcome of the round (0 if you lost, 3 if the round was a draw, and 6 if you won).
+    """
+    score = 0
+    me_lu = {"X": "lose", "Y": "draw", "Z": "win"}
+    lu = {"A": 1, "B": 2, "C": 3}
+    # 2 > 1
+    # 3 > 2
+    # 1 > 3
+    for line in s.split('\n'):
+        if line.strip() == "":
+            continue
+        elf, _, me = line
+        goal = me_lu[me]
+        if goal == "draw":
+            score += lu[elf] + 3
+        elif goal == "lose":
+            if lu[elf] == 1:
+                score += 3
+            else:
+                score += lu[elf] - 1
+        else:
+            if lu[elf] == 3:
+                score += 6 + 1
+            else:
+                score += 6 + lu[elf] + 1
+    return score
+
+
+INPUT_S = '''\
+1000
+
+2000
+
+5000
+
+1000
+4001
+'''
+EXPECTED = 5001
+
+
+@pytest.mark.parametrize(
+    ('input_s', 'expected'),
+    (
+        (INPUT_S, EXPECTED),
+    ),
+)
+def test(input_s: str, expected: int) -> None:
+    assert compute(input_s) == expected
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('data_file', nargs='?', default=INPUT_TXT)
+    args = parser.parse_args()
+
+    with open(args.data_file) as f, support.timing():
+        print(compute(f.read()))
+
+    return 0
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())