1 files changed, 17 insertions(+), 4 deletions(-)

M day7.nim

@@ 56,9 56,15 @@ proc readRules(input: seq[string]): RulesTable =
                 ret[bag_name].add(bagContentFromStr(entry))
     ret
 
-proc part1(input: seq[string]): int =
-    let rules = readRules(input)
-    let target = "shiny gold"
+proc countSubBags(contents: seq[BagContent], rules: RulesTable): int =
+    var ret = 1 # Start with the current bag as 1
+    # Count bags in this level, and all children
+    for entry in contents:
+        let subentry = rules[entry.name]
+        ret += entry.amt * subentry.countSubBags(rules)
+    ret
+
+proc part1(rules: RulesTable, target: string): int =
     var res = 0
     # Read every single entry.
     for contents in rules.values:


@@ 70,6 76,13 @@ proc part1(input: seq[string]): int =
             continue
     res
 
+proc part2(rules: RulesTable, target: string): int =
+    let top = rules[target]
+    top.countSubBags(rules) - 1 # Ignore top-level bag
+
 proc day7*() =
     let input = readLinesToStrSeq("puzzles/day7.txt")
-    echo "Part 1: ", part1(input)>
\ No newline at end of file
+    let rules = readRules(input)
+    let target = "shiny gold"
+    echo "Part 1: ", part1(rules, target)
+    echo "Part 2: ", part2(rules, target)<
\ No newline at end of file