Advent of Code 2021 - Day 3
Here is my solution for Day 3. I am using three different loops to keep things simple rather than a more optimized solution.
I am also pushing these solutions to Github if you prefer that - https://github.com/Bukkaraya/AoC_2021
def bin_to_int(str):
return int(str, 2)
def get_bits_in_column(arr, col_num):
bits = []
for a in arr:
bits.append(a[i])
return bits
if __name__ == "__main__":
with open("input.txt", "r") as f:
readings = f.read().split("\n")
gamma = ""
epsilon = ""
oxygen_readings = readings
co2_readings = readings
for i in range(len(readings[0])):
bits = get_bits_in_column(readings, i)
if bits.count('1') > bits.count('0'):
gamma += "1"
epsilon += "0"
else:
gamma += "0"
epsilon += "1"
for i in range(len(readings[0])):
if len(oxygen_readings) == 1:
break
bits = bits = get_bits_in_column(oxygen_readings, i)
if bits.count('1') >= bits.count('0'):
oxygen_readings = [r for r in oxygen_readings if r[i] == '1']
else:
oxygen_readings = [r for r in oxygen_readings if r[i] == '0']
for i in range(len(readings[0])):
if len(co2_readings) == 1:
break
bits = get_bits_in_column(co2_readings, i)
if bits.count('1') >= bits.count('0'):
co2_readings = [r for r in co2_readings if r[i] == '0']
else:
co2_readings = [r for r in co2_readings if r[i] == '1']
gamma = bin_to_int(gamma)
epsilon = bin_to_int(epsilon)
print(f"Result for Part 1: {gamma * epsilon}")
oxygen_reading = bin_to_int(oxygen_readings[0])
co2_reading = bin_to_int(co2_readings[0])
print(f"Result for Part 2: {oxygen_reading * co2_reading}")