Solution to problem 17 in Python

src/Year_2015/P17.py

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+# --- Day 17: No Such Thing as Too Much ---
+
+# The elves bought too much eggnog again - 150 liters this time. To fit it all
+# into your refrigerator, you'll need to move it into smaller containers. You
+# take an inventory of the capacities of the available containers.
+
+# For example, suppose you have containers of size 20, 15, 10, 5, and 5 liters.
+# If you need to store 25 liters, there are four ways to do it:
+
+#     15 and 10
+#     20 and 5 (the first 5)
+#     20 and 5 (the second 5)
+#     15, 5, and 5
+
+# Filling all containers entirely, how many different combinations of containers
+# can exactly fit all 150 liters of eggnog?
+
+from itertools import combinations
+
+with open("files/P17.txt") as f:
+    containers = [int(c) for c in f.read().strip().split()]
+
+
+def part_1():
+    total = 0
+    for i, _ in enumerate(containers):
+        for combination in combinations(containers, i):
+            if sum(combination) == 150:
+                total += 1
+    print(f"There are {total} different combinations")
+
+
+# --- Part Two ---
+
+# While playing with all the containers in the kitchen, another load of eggnog
+# arrives! The shipping and receiving department is requesting as many
+# containers as you can spare.
+
+# Find the minimum number of containers that can exactly fit all 150 liters of
+# eggnog. How many different ways can you fill that number of containers and
+# still hold exactly 150 litres?
+
+# In the example above, the minimum number of containers was two. There were
+# three ways to use that many containers, and so the answer there would be 3.
+
+
+def part_2():
+    minimum = 0
+    for i, _ in enumerate(containers):
+        for combination in combinations(containers, i):
+            if sum(combination) == 150:
+                minimum += 1
+        if minimum:
+            break
+    print(f"The minimum number of containers is {minimum}")
+
+
+if __name__ == "__main__":
+    part_1()
+    part_2()