Solution to problem 3 part 2 in Python

src/Year_2021/P3.py

@@ -52,6 +52,8 @@
 # of the submarine? (Be sure to represent your answer in decimal, not binary.)
 
 from collections import Counter
+from enum import EnumMeta
+from typing import Any, Dict
 
 with open("files/P3.txt", "r") as f:
     diagnostics = [number for number in f.read().strip().split()]
@@ -87,5 +89,111 @@ def part_1() -> None:
     print(f"Power consumption is {gamma*epsilon}")
 
 
+# --- Part Two ---
+
+# Next, you should verify the life support rating, which can be determined by
+# multiplying the oxygen generator rating by the CO2 scrubber rating.
+
+# Both the oxygen generator rating and the CO2 scrubber rating are values that
+# can be found in your diagnostic report - finding them is the tricky part.
+# Both values are located using a similar process that involves filtering out
+# values until only one remains. Before searching for either rating value,
+# start with the full list of binary numbers from your diagnostic report and
+# consider just the first bit of those numbers. Then:
+
+#     Keep only numbers selected by the bit criteria for the type of rating
+# value for which you are searching. Discard numbers which do not match the bit
+# criteria.
+#     If you only have one number left, stop; this is the rating value for
+# which you are searching.
+#     Otherwise, repeat the process, considering the next bit to the right.
+
+# The bit criteria depends on which type of rating value you want to find:
+
+#     To find oxygen generator rating, determine the most common value (0 or 1)
+# in the current bit position, and keep only numbers with that bit in that
+# position. If 0 and 1 are equally common, keep values with a 1 in the position
+# being considered.
+#     To find CO2 scrubber rating, determine the least common value (0 or 1) in
+# the current bit position, and keep only numbers with that bit in that
+# position. If 0 and 1 are equally common, keep values with a 0 in the position
+# being considered.
+
+# For example, to determine the oxygen generator rating value using the same
+# example diagnostic report from above:
+
+#     Start with all 12 numbers and consider only the first bit of each number.
+# There are more 1 bits (7) than 0 bits (5), so keep only the 7 numbers with a
+# 1 in the first position: 11110, 10110, 10111, 10101, 11100, 10000, and 11001.
+#     Then, consider the second bit of the 7 remaining numbers: there are more
+# 0 bits (4) than 1 bits (3), so keep only the 4 numbers with a 0 in the second
+# position: 10110, 10111, 10101, and 10000.
+#     In the third position, three of the four numbers have a 1, so keep those
+# three: 10110, 10111, and 10101.
+#     In the fourth position, two of the three numbers have a 1, so keep those
+# two: 10110 and 10111.
+#     In the fifth position, there are an equal number of 0 bits and 1 bits
+# (one each). So, to find the oxygen generator rating, keep the number with a 1
+# in that position: 10111.
+#     As there is only one number left, stop; the oxygen generator rating is
+# 10111, or 23 in decimal.
+
+# Then, to determine the CO2 scrubber rating value from the same example above:
+
+#     Start again with all 12 numbers and consider only the first bit of each
+# number. There are fewer 0 bits (5) than 1 bits (7), so keep only the 5
+# numbers with a 0 in the first position: 00100, 01111, 00111, 00010, and
+# 01010.
+#     Then, consider the second bit of the 5 remaining numbers: there are fewer
+# 1 bits (2) than 0 bits (3), so keep only the 2 numbers with a 1 in the second
+# position: 01111 and 01010.
+#     In the third position, there are an equal number of 0 bits and 1 bits
+# (one each). So, to find the CO2 scrubber rating, keep the number with a 0 in
+# that position: 01010.
+#     As there is only one number left, stop; the CO2 scrubber rating is 01010,
+# or 10 in decimal.
+
+# Finally, to find the life support rating, multiply the oxygen generator
+# rating (23) by the CO2 scrubber rating (10) to get 230.
+
+# Use the binary numbers in your diagnostic report to calculate the oxygen
+# generator rating and CO2 scrubber rating, then multiply them together. What
+# is the life support rating of the submarine? (Be sure to represent your
+# answer in decimal, not binary.)
+
+
+def get_bin_num(lst, idx=None, o2=True) -> str:
+    ones = [line for line in lst if line[idx] == "1"]
+    zeros = [line for line in lst if line[idx] == "0"]
+
+    if o2:
+        if len(ones) == len(zeros) == 1:
+            o2_list = "".join(ones if ones[0][idx] == "1" else zeros)
+            return o2_list
+        else:
+            return get_bin_num(
+                ones if len(ones) >= len(zeros) else zeros, idx + 1
+            )
+    else:
+        if len(ones) == len(zeros) == 1:
+            co2_list = "".join(ones if ones[0][idx] == "0" else zeros)
+            return co2_list
+        else:
+            return get_bin_num(
+                ones if len(ones) < len(zeros) else zeros, idx + 1, o2=False
+            )
+
+
+def part_2() -> None:
+    o2_bin_str = get_bin_num(lst=diagnostics, idx=0)
+    co2_bin_str = get_bin_num(lst=diagnostics, idx=0, o2=False)
+
+    o2 = int("".join(o2_bin_str), 2)
+    co2 = int("".join(co2_bin_str), 2)
+
+    print(f"Power consumption is {o2*co2}")
+
+
 if __name__ == "__main__":
     part_1()
+    part_2()