public string Solve()
{
var passportEntries = ResourceUtilities.ReadResource("Day4.Input.txt").Split("\r\n\r\n").Select(x => x.Replace("\r\n", " ")).ToList();
var passportRegex = new Regex("(?=.*byr)(?=.*iyr)(?=.*eyr)(?=.*hgt)(?=.*hcl)(?=.*ecl)(?=.*pid)");
return(passportEntries.Count(x => passportRegex.IsMatch(x)).ToString());
}
public string Solve()
{
var numbers = ResourceUtilities.ReadResource("Day1.Input.txt").Split("\r\n").Select(int.Parse).ToList();
var(num1, num2) = numbers.SelectMany((x, index) => numbers.Skip(index + 1)
.Select(y => (Num1: x, Num2: y)))
.Single(x => x.Num1 + x.Num2 == 2020);
return($"{num1 * num2}");
}
public string Solve()
{
var inputs = ResourceUtilities.ReadResource("Day2.Input.txt").Split("\r\n").ToList();
var inputParsingRegex = new Regex("(\\d+)-(\\d+) ([a-z]): ([a-z]+)");
return(inputs.Select(x => inputParsingRegex.Match(x))
.Select(x => (LowerLimit: x.CaptureInt(1), UpperLimit: x.CaptureInt(2), Letter: x.CaptureChar(3), Input: x.CaptureString(4)))
.Count(x => x.Input.Count(y => y == x.Letter) >= x.LowerLimit && x.Input.Count(y => y == x.Letter) <= x.UpperLimit)
.ToString());
}
public string Solve()
{
var numbers = ResourceUtilities.ReadResource("Day1.Input.txt").Split("\r\n").Select(int.Parse).ToList();
var(num1, num2, num3) = numbers.SelectMany((x, index1) => numbers.Skip(index1 + 1)
.SelectMany((y, index2) => numbers.Skip(index1 + index2 + 2)
.Select(z => (Num1: x, Num2: y, Num3: z))))
.Single(x => x.Num1 + x.Num2 + x.Num3 == 2020);
return($"{num1 * num2 * num3}");
}
public string Solve()
{
var inputs = ResourceUtilities.ReadResource("Day2.Input.txt").Split("\r\n").ToList();
var inputParsingRegex = new Regex("(\\d+)-(\\d+) ([a-z]): ([a-z]+)");
return(inputs.Select(x => inputParsingRegex.Match(x))
.Select(x => (FirstIndex: x.CaptureInt(1), SecondIndex: x.CaptureInt(2), Letter: x.CaptureChar(3), Input: x.CaptureString(4)))
.Count(x => new Regex($"^.{{{x.FirstIndex - 1}}}{x.Letter}").IsMatch(x.Input) && new Regex($"^.{{{x.SecondIndex - 1}}}{x.Letter}").IsMatch(x.Input) == false ||
new Regex($"^.{{{x.FirstIndex - 1}}}{x.Letter}").IsMatch(x.Input) == false && new Regex($"^.{{{x.SecondIndex - 1}}}{x.Letter}").IsMatch(x.Input))
.ToString());
}
public string Solve()
{
var terrainPoints = ResourceUtilities.ReadResource("Day3.Input.txt").Split("\r\n").Select(x => x.ToCharArray()).ToList();
return(new List <Func <char[], int, int?> > {
CalculatePositionRight1Down1, CalculatePositionRight3Down1, CalculatePositionRight5Down1, CalculatePositionRight7Down1, CalculatePositionRight1Down2
}
.Select(func => terrainPoints.Skip(1)
.Select((mapRow, row) => ReadMapSymbolAtPosition(mapRow, func(mapRow, row)))
.Count(PointIsTree))
.Aggregate(1, (product, numTrees) => product * numTrees)
.ToString());
}
public string Solve()
{
var passportEntries = ResourceUtilities.ReadResource("Day4.Input.txt").Split("\r\n\r\n").Select(x => x.Replace("\r\n", " ")).ToList();
var passportParsingRegex = new Regex("(?=.*byr:([^ ]*))(?=.*iyr:([^ ]*))(?=.*eyr:([^ ]*))(?=.*hgt:([^ ]*))(?=.*hcl:([^ ]*))(?=.*ecl:([^ ]*))(?=.*pid:([^ ]*))");
return(passportEntries.Select(x => passportParsingRegex.Match(x))
.Where(x => x.Success)
.Select(x => (BYR: x.CaptureInt(1), IYR: x.CaptureInt(2), EYR: x.CaptureInt(3), HGT: x.CaptureString(4), HCL: x.CaptureString(5), ECL: x.CaptureString(6), PID: x.CaptureString(7)))
.Where(x => x.BYR >= 1920 && x.BYR <= 2002)
.Where(x => x.IYR >= 2010 && x.IYR <= 2020)
.Where(x => x.EYR >= 2020 && x.EYR <= 2030)
.Where(x => new Regex("^([0-9]+)cm$").Match(x.HGT).CaptureInt(1) >= 150 &&
new Regex("^([0-9]+)cm$").Match(x.HGT).CaptureInt(1) <= 193 ||
new Regex("^([0-9]+)in$").Match(x.HGT).CaptureInt(1) >= 59 &&
new Regex("^([0-9]+)in$").Match(x.HGT).CaptureInt(1) <= 76)
.Where(x => new Regex("^#[0-9a-f]{6}$").IsMatch(x.HCL))
.Where(x => new Regex("^amb|blu|brn|gry|grn|hzl|oth$").IsMatch(x.ECL))
.Where(x => new Regex("^\\d{9}$").IsMatch(x.PID))
.Count()
.ToString());
}
public string Solve()
{
var terrainPoints = ResourceUtilities.ReadResource("Day3.Input.txt").Split("\r\n").Select(x => x.ToCharArray()).ToList();
return(terrainPoints.Skip(1).Select((mapRow, row) => mapRow[CalculatePosition(mapRow, row)]).Count(PointIsTree).ToString());
}
