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clean up day 7 a bit

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This commit is contained in:
Colin McMillen 2020-12-08 15:02:56 -05:00
parent 314eaa841a
commit 13d5d6c9d1
1 changed files with 7 additions and 6 deletions
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13
2020/Day07.cs
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@ -46,11 +46,12 @@ namespace AdventOfCode {
return contains; return contains;
} }
static int ComputePart1(List<Contains> contains) { static int WhatCanContain(List<Contains> contains, string target) {
int setSize = 0;
var result = new HashSet<string>(); var result = new HashSet<string>();
result.Add("shiny gold"); int setSize = 0;
result.Add(target);
// transitive closure: keep adding things, until a round of doing so doesn't add anything new
while (true) { while (true) {
foreach (Contains c in contains) { foreach (Contains c in contains) {
if (result.Contains(c.Inner)) { if (result.Contains(c.Inner)) {
@ -58,7 +59,7 @@ namespace AdventOfCode {
} }
} }
if (result.Count() == setSize) { // nothing new to add, we're done if (result.Count() == setSize) { // nothing new to add, we're done
return result.Count() - 1; // shiny gold doesn't contain itself return result.Count() - 1; // our target doesn't actually contain itself
} }
setSize = result.Count(); setSize = result.Count();
} }
@ -76,7 +77,7 @@ namespace AdventOfCode {
static int Part1() { static int Part1() {
List<Contains> contains = ParseRules(File.ReadAllLines(Util.RootDir + "day07.txt")); List<Contains> contains = ParseRules(File.ReadAllLines(Util.RootDir + "day07.txt"));
return ComputePart1(contains); return WhatCanContain(contains, "shiny gold");
} }
static int Part2() { static int Part2() {
@ -97,7 +98,7 @@ vibrant plum bags contain 5 faded blue bags, 6 dotted black bags.
faded blue bags contain no other bags. faded blue bags contain no other bags.
dotted black bags contain no other bags.".Split('\n'); dotted black bags contain no other bags.".Split('\n');
Assert.Equal(4, ComputePart1(ParseRules(example))); Assert.Equal(4, WhatCanContain(ParseRules(example), "shiny gold"));
Assert.Equal(213, Part1()); Assert.Equal(213, Part1());
string[] example2 = string[] example2 =