Solution to problem 2 in Python

src/Year_2023/Day02.py

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+# --- Day 2: Cube Conundrum ---
+
+# You're launched high into the atmosphere! The apex of your trajectory just
+# barely reaches the surface of a large island floating in the sky. You gently
+# land in a fluffy pile of leaves. It's quite cold, but you don't see much snow.
+# An Elf runs over to greet you.
+
+# The Elf explains that you've arrived at Snow Island and apologizes for the
+# lack of snow. He'll be happy to explain the situation, but it's a bit of a
+# walk, so you have some time. They don't get many visitors up here; would you
+# like to play a game in the meantime?
+
+# As you walk, the Elf shows you a small bag and some cubes which are either
+# red, green, or blue. Each time you play this game, he will hide a secret
+# number of cubes of each color in the bag, and your goal is to figure out
+# information about the number of cubes.
+
+# To get information, once a bag has been loaded with cubes, the Elf will reach
+# into the bag, grab a handful of random cubes, show them to you, and then put
+# them back in the bag. He'll do this a few times per game.
+
+# You play several games and record the information from each game (your puzzle
+# input). Each game is listed with its ID number (like the 11 in Game 11: ...)
+# followed by a semicolon-separated list of subsets of cubes that were revealed
+# from the bag (like 3 red, 5 green, 4 blue).
+
+# For example, the record of a few games might look like this:
+
+# Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+# Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+# Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+# Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+# Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green
+
+# In game 1, three sets of cubes are revealed from the bag (and then put back
+# again). The first set is 3 blue cubes and 4 red cubes; the second set is 1 red
+# cube, 2 green cubes, and 6 blue cubes; the third set is only 2 green cubes.
+
+# The Elf would first like to know which games would have been possible if the
+# bag contained only 12 red cubes, 13 green cubes, and 14 blue cubes?
+
+# In the example above, games 1, 2, and 5 would have been possible if the bag
+# had been loaded with that configuration. However, game 3 would have been
+# impossible because at one point the Elf showed you 20 red cubes at once;
+# similarly, game 4 would also have been impossible because the Elf showed you
+# 15 blue cubes at once. If you add up the IDs of the games that would have been
+# possible, you get 8.
+
+# Determine which games would have been possible if the bag had been loaded with
+# only 12 red cubes, 13 green cubes, and 14 blue cubes. What is the sum of the
+# IDs of those games?
+
+with open("files/P2.txt") as f:
+    games = [line for line in f.read().strip().split("\n")]
+
+limit = {"red": 12, "green": 13, "blue": 14}
+
+
+def part1():
+    total = 0
+    for game in games:
+        id = int(game.split(":")[0].split()[1])
+        subgames = game.split(":")[1].strip().split("; ")
+        valid = True
+        for subgame in subgames:
+            for items in subgame.split(", "):
+                number, color = items.split()
+                if limit[color] < int(number):
+                    valid = False
+                    break
+        if valid:
+            total += id
+    print(f"The sum of the IDs is {total}")
+
+
+# --- Part Two ---
+
+# The Elf says they've stopped producing snow because they aren't getting any
+# water! He isn't sure why the water stopped; however, he can show you how to
+# get to the water source to check it out for yourself. It's just up ahead!
+
+# As you continue your walk, the Elf poses a second question: in each game you
+# played, what is the fewest number of cubes of each color that could have been
+# in the bag to make the game possible?
+
+# Again consider the example games from earlier:
+
+# Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+# Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+# Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+# Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+# Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green
+
+#     In game 1, the game could have been played with as few as 4 red, 2 green,
+# and 6 blue cubes. If any color had even one fewer cube, the game would have
+# been impossible.
+#     Game 2 could have been played with a minimum of 1 red, 3 green, and 4 blue
+# cubes.
+#     Game 3 must have been played with at least 20 red, 13 green, and 6 blue
+# cubes.
+#     Game 4 required at least 14 red, 3 green, and 15 blue cubes.
+#     Game 5 needed no fewer than 6 red, 3 green, and 2 blue cubes in the bag.
+
+# The power of a set of cubes is equal to the numbers of red, green, and blue
+# cubes multiplied together. The power of the minimum set of cubes in game 1 is
+# 48. In games 2-5 it was 12, 1560, 630, and 36, respectively. Adding up these
+# five powers produces the sum 2286.
+
+# For each game, find the minimum set of cubes that must have been present.
+# What is the sum of the power of these sets?
+
+from math import prod
+
+
+def part2():
+    total = 0
+    for g in games:
+        game = {"red": 0, "green": 0, "blue": 0}
+        subgames = g.split(":")[1].strip().split("; ")
+        for subgame in subgames:
+            for items in subgame.split(", "):
+                number, color = items.split()
+                game[color] = max(game[color], int(number))
+        total += prod(game.values())
+    print(f"The sum of the power is {total}")
+
+
+if __name__ == "__main__":
+    part1()
+    part2()