Day 3 part 2

.gitignore

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+.idea
+*.swp

3/3_2.py

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+#!/usr/bin/env python
+# 2021 - Advent Of Code - 3 part2
+
+import re
+
+re_parse = re.compile(r'(\d)'*12)
+MOST = 1
+LEAST = 0
+
+
+def freq_bits(buf, mode):
+    count = [0] * 12
+    co2_freq = [0] * 12
+    oxy = [0] * 12
+    for line in buf:
+        m = re_parse.match(line)
+
+        for i in range(12):
+            if m.group(i+1) == '1':
+                count[i] += 1
+
+    for i in range(12):
+        if count[i] >= len(buf) / 2:
+            oxy[i] = 1
+        else:
+            oxy[i] = 0
+
+    for i in range(12):
+        if count[i] > len(buf) / 2:
+            co2_freq[i] = 1
+        else:
+            co2_freq[i] = 0
+
+    if mode == MOST:
+        return oxy
+    elif mode == LEAST:
+        co2_freq = [0 if x == 1 else 1 for x in oxy]
+        return co2_freq
+
+
+def filter_pos(line_buffer, position, value):
+    for line in line_buffer:
+        if line[position] == value:
+            yield line
+
+
+def filter_freq(buffer, freq_buf, mode):
+    i = 0
+    while i in range(12) and len(buffer) > 1:
+        buffer = list(filter_pos(buffer, i, str(freq_buf[i])))
+        freq_buf = freq_bits(buffer, mode)
+        print(len(buffer))
+        i += 1
+
+    return buffer
+
+
+line_buf = []
+with open('input.txt') as f:
+    for line in f:
+        line_buf.append(line)
+
+gamma_count = freq_bits(line_buf, MOST)
+gamma_bin = "".join([str(x) for x in gamma_count])
+gamma = int(gamma_bin, 2)
+
+epsilon_count = freq_bits(line_buf, LEAST)
+epsilon_bin = "".join([str(x) for x in epsilon_count])
+epsilon = int(epsilon_bin, 2)
+
+print(f'gamma_bin   {gamma_bin}, gamma: {gamma}')
+print(f'epsilon_bin {epsilon_bin}, epsilon: {epsilon}')
+
+oxybuf = filter_freq(line_buf, gamma_count, MOST)
+co2buf = filter_freq(line_buf, epsilon_count, LEAST)
+
+oxygen = int(oxybuf[0].strip(), 2)
+print(f'oxybuf: {oxybuf}, oxygen: {oxygen}')
+
+co2 = int(co2buf[0].strip(), 2)
+print(f'co2buf: {co2buf}, co2: {co2}')
+print(f'life support: {oxygen}, {co2} => {oxygen * co2}')