Add day03 2021

2021/day03.py

@@ -0,0 +1,70 @@
+#!/usr/bin/python3
+"""
+Jour 03 du défi Advent Of Code pour l'année 2021
+"""
+
+def read_sample():
+    """récupère les entrées depuis le fichier texte correspondant"""
+    with open('inputs/day03.txt', 'r') as file:
+        sample = file.read().split('\n')
+    sample = [ i for i in sample if i != '' ]
+    return sample
+
+def bin_to_dec(binary):
+    """Converts a binary number to an int"""
+    binary = str(binary)
+    decimal = 0
+    for i, _ in enumerate(binary):
+        decimal = decimal*2
+        decimal += int(binary[i])
+    return decimal
+
+def comm(sample, bit):
+    """Determines the most common bit in an array"""
+    mst_com = {"0":0, "1":0}
+    for i in sample:
+        mst_com[i[bit]] += 1
+    if mst_com["0"] > mst_com["1"]:
+        return ("0", "1")
+    if mst_com["0"] < mst_com["1"]:
+        return ("1", "0")
+    return("1", "0")
+
+def part1(sample):
+    """Partie 1 du défi"""
+    number1 = ""
+    number2 = ""
+    for i in range(len(sample[0])):
+        a, b = comm(sample, i)
+        number1 += a
+        number2 += b
+    gamma_rate = bin_to_dec(number1)
+    epsilon_rate = bin_to_dec(number2)
+    return gamma_rate*epsilon_rate
+
+
+def loop(oxygen, co2, bit):
+    """Fonction principale récursive du second défi"""
+    if len(oxygen) == 1 and len(co2) == 1:
+        return bin_to_dec(oxygen[0]) * bin_to_dec(co2[0])
+
+    mst_com, _ = comm(oxygen, bit)
+    _, lst_com = comm(co2, bit)
+
+    if len(oxygen) > 1:
+        oxygen = [ i for i in oxygen if i[bit] == mst_com ]
+    if len(co2) > 1:
+        co2 = [ i for i in co2 if i[bit] == lst_com ]
+
+    return loop(oxygen, co2, bit+1)
+
+def part2(sample):
+    """Partie 2"""
+    return loop(sample.copy(), sample.copy(), 0)
+
+
+def main():
+    """Fonction principale"""
+    sample = read_sample()
+    print(f"part1: {part1(sample)}")
+    print(f"part2: {part2(sample)}")