public override object SolveOne()
{
return(IntRows
.Where(x => IntRows.Contains(2020 - x))
.Select(x => x * (2020 - x))
.First());
}
long CountPaths(int current)
{
if (current == Max)
{
return(1);
}
return(IntRows.Where(x => x > current && x <= current + 3).Sum(x =>
{
if (!Memo.ContainsKey(x))
{
Memo[x] = CountPaths(x);
}
return Memo[x];
}));
}
public override object SolveOne()
{
int[] hops = new int[] { 0, 0, 0 };
int joltage = 0;
while (true)
{
if (joltage == Max)
{
return(hops[0] * (hops[2] + 1));
}
int next = IntRows.Where(x => x > joltage).Min();
hops[next - joltage - 1]++;
joltage = next;
}
}
public override object SolveTwo()
{
return(IntRows
.Where(x => IntRows.Exists(y => IntRows.Contains(2020 - x - y)))
.Aggregate(1, (x, y) => x * y));
}
public Day10()
{
Max = IntRows.Max();
}