Day 03

day03/part1.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python3
+
+lines = (x.strip() for x in open("input.txt"))
+
+cnt = [0] * 12
+
+for line in lines:
+    cnt = [x+(int(char)*2-1) for x, char in zip(cnt, line)]
+
+gamma = int(''.join(['1' if x > 0 else '0' for x in cnt]), 2)
+epsilon = int(''.join(['1' if x < 0 else '0' for x in cnt]), 2)
+
+print(gamma * epsilon)

day03/part2.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+
+
+def find(is_lowest):
+    lines = (x.strip() for x in open("input.txt"))
+    for bit in range(12):
+        zeros = []
+        ones = []
+        for line in lines:
+            zeros.append(line) if line[bit] == '0' else ones.append(line)
+        lines = zeros if (len(zeros) > len(ones)) != is_lowest else ones
+        if len(lines) <= 1:
+            break
+    return lines[0]
+
+
+gamma = int(''.join(find(True)), 2)
+epsilon = int(''.join(find(False)), 2)
+
+print(gamma * epsilon)

newday.sh

@@ -27,3 +27,6 @@ curl --request GET -sL \
      --cookie "session=$AOC_SESSION" \
      --url "https://adventofcode.com/2021/day/$(echo $1 | sed 's/^0*//')/input"\
      --output "$f/input.txt"
+
+# git
+git add "$f/*"