|
|
@ -10,13 +10,13 @@ namespace AdventOfCode { |
|
|
|
|
|
|
|
public class Day09 { |
|
|
|
|
|
|
|
static bool Valid(List<long> ints, int preambleSize, int target) { |
|
|
|
static bool Valid(List<long> longs, int preambleSize, int target) { |
|
|
|
for (int i = target - preambleSize; i < target - 1; i++) { |
|
|
|
for (int j = i + 1; j < target; j++) { |
|
|
|
if (i == j) { |
|
|
|
continue; |
|
|
|
} |
|
|
|
if (ints[i] + ints[j] == ints[target]) { |
|
|
|
if (longs[i] + longs[j] == longs[target]) { |
|
|
|
return true; |
|
|
|
} |
|
|
|
} |
|
|
@ -24,10 +24,10 @@ namespace AdventOfCode { |
|
|
|
return false; |
|
|
|
} |
|
|
|
|
|
|
|
static long FindInvalid(List<long> ints, int preambleSize) { |
|
|
|
for (int target = preambleSize; target < ints.Count(); target++) { |
|
|
|
if (!Valid(ints, preambleSize, target)) { |
|
|
|
return ints[target]; |
|
|
|
static long FindInvalid(List<long> longs, int preambleSize) { |
|
|
|
for (int target = preambleSize; target < longs.Count(); target++) { |
|
|
|
if (!Valid(longs, preambleSize, target)) { |
|
|
|
return longs[target]; |
|
|
|
} |
|
|
|
} |
|
|
|
throw new Exception("didn't find an invalid int"); |
|
|
@ -35,8 +35,8 @@ namespace AdventOfCode { |
|
|
|
|
|
|
|
static long Part1() { |
|
|
|
string[] input = File.ReadAllLines(Util.RootDir + "day09.txt"); |
|
|
|
List<long> ints = input.ToList().Select(long.Parse).ToList(); |
|
|
|
return FindInvalid(ints, 25); |
|
|
|
List<long> longs = input.ToList().Select(long.Parse).ToList(); |
|
|
|
return FindInvalid(longs, 25); |
|
|
|
} |
|
|
|
|
|
|
|
static int Part2() { |
|
|
@ -66,8 +66,8 @@ namespace AdventOfCode { |
|
|
|
277 |
|
|
|
309 |
|
|
|
576".Split('\n');
|
|
|
|
List<long> ints = example.ToList().Select(long.Parse).ToList(); |
|
|
|
Assert.Equal(127, FindInvalid(ints, 5)); |
|
|
|
List<long> longs = example.ToList().Select(long.Parse).ToList(); |
|
|
|
Assert.Equal(127, FindInvalid(longs, 5)); |
|
|
|
|
|
|
|
Assert.Equal(50047984, Part1()); |
|
|
|
Assert.Equal(-1, Part2()); |
|
|
|