private static string GetDay1Part2(IEnumerable <int> expenseReport)
{
var result = string.Empty;
foreach (var combination in EnumerableCombinations.GetCombinations(expenseReport.ToArray(), 3))
{
if (combination[0] + combination[1] + combination[2] != 2020)
{
continue;
}
result = $"Part 2 Product of combinations = {combination[0] * combination[1] * combination[2]}";
break;
}
return(result);
}
private static bool IsSumPresent(long[] arrayToCheck, long currentIndexValue, int numberOfElementsToSum) => EnumerableCombinations.GetCombinations(arrayToCheck, numberOfElementsToSum).Any(combination => combination.Sum() == currentIndexValue);