Add day 3 solution

day-03/day-03.py

@@ -0,0 +1,66 @@
+#!/usr/bin/python3
+
+def part_1(input):
+    result = 0
+    gamma = 0
+    epsilon = 0
+    num_bits = len(input[0]) - 1
+    counts = [0] * num_bits
+    for line in input:
+        line = int(line, 2)
+        for i in range(num_bits):
+            shift = (num_bits - i - 1)
+            mask = 1 << shift
+            if mask & line:
+                counts[i] += 1
+    for count in counts:
+        gamma <<= 1
+        epsilon <<= 1
+        if len(input)/2 < count:
+            gamma |= 1
+        else:
+            epsilon |= 1
+    result = gamma * epsilon
+    print("Part 1 result:", result)
+
+
+def part_2(input):
+    result = 0
+    num_bits = len(input[0]) - 1
+    oxy_list = input.copy()
+    co2_list = input.copy()
+    for i in range(num_bits):
+        shift = (num_bits - i - 1)
+        mask = 1 << shift
+        count = 0
+        for element in list(oxy_list):
+            if int(element, 2) & mask:
+                count += 1
+        digit = 0
+        if (len(oxy_list)/2) <= count:
+            digit = 1
+        for element in list(oxy_list):
+            if (int(element, 2) & mask) >> shift != digit:
+                if 1 < len(oxy_list):
+                    oxy_list.remove(element)
+        count = 0
+        for element in list(co2_list):
+            if int(element, 2) & mask:
+                count += 1
+        digit = 1
+        if (len(co2_list)/2) <= count:
+            digit = 0
+        for element in list(co2_list):
+            if (int(element, 2) & mask) >> shift != digit:
+                if 1 < len(co2_list):
+                    co2_list.remove(element)
+    result = int(oxy_list[0], 2) * int(co2_list[0], 2)
+    print("Part 2 result:", result)
+
+
+input = list()
+with open('input.txt') as fp:
+    input = fp.readlines()
+
+part_1(input)
+part_2(input)