76 lines
2.8 KiB
C#
76 lines
2.8 KiB
C#
using System.Collections.Generic;
|
|
using System.IO;
|
|
using System.Linq;
|
|
using AdvenOfCode.Contracts;
|
|
using Coordinate = (int x, int y);
|
|
|
|
namespace AoC_2025;
|
|
|
|
public class Day06 : IPuzzleSolver<long>
|
|
{
|
|
private (string[] operands, string[] numbers) ParsePuzzleInput(string path)
|
|
{
|
|
var puzzleInput = File.ReadAllLines(path)
|
|
.Where(line => !string.IsNullOrWhiteSpace(line))
|
|
.ToArray();
|
|
var operands = puzzleInput[^1]
|
|
.Split(' ', StringSplitOptions.RemoveEmptyEntries);
|
|
var numbers = puzzleInput[..^1];
|
|
return (operands, numbers);
|
|
}
|
|
|
|
public long SolvePart1(string pathToPuzzleInput)
|
|
{
|
|
var calculations = ParsePuzzleInput(pathToPuzzleInput);
|
|
var numbers = calculations.numbers
|
|
.Select(line => line.Split(' ', StringSplitOptions.RemoveEmptyEntries))
|
|
.Select(line => line.Index().ToArray())
|
|
.SelectMany(tuples => tuples.Select(tuple => (tuple.Index, long.Parse(tuple.Item))).ToArray())
|
|
.ToArray();
|
|
var pivotedNumbers = numbers.GroupBy(tuple => tuple.Index);
|
|
var indexedOperands = calculations.operands
|
|
.Index()
|
|
.Select(tuple => (tuple.Index, ParseOperand(tuple.Item)))
|
|
.ToDictionary();
|
|
var results = pivotedNumbers.Select(group =>
|
|
group
|
|
.Select(tuple => tuple.Item2)
|
|
.Aggregate(indexedOperands[group.Key].opBaseValue,
|
|
(acc, number) => indexedOperands[group.Key].operation(acc, number)));
|
|
return results.Sum();
|
|
}
|
|
|
|
public long SolvePart2(string pathToPuzzleInput)
|
|
{
|
|
var calculations = ParsePuzzleInput(pathToPuzzleInput);
|
|
var operands = calculations.operands.Select(ParseOperand).Reverse().ToArray();
|
|
List<List<long>> numberColumns = [];
|
|
List<long> currentColumn = [];
|
|
for (var i = 1; i <= calculations.numbers[0].Length; i++)
|
|
{
|
|
var current = calculations.numbers.Aggregate("", (current1, number) => current1 + number[^i]);
|
|
|
|
if (!string.IsNullOrWhiteSpace(current))
|
|
{
|
|
currentColumn.Add(long.Parse(current));
|
|
}
|
|
else
|
|
{
|
|
numberColumns.Add(currentColumn);
|
|
currentColumn = [];
|
|
}
|
|
}
|
|
numberColumns.Add(currentColumn);
|
|
|
|
return numberColumns
|
|
.Select((column, colIndex) => column.Aggregate(operands[colIndex].opBaseValue, (acc, next) => operands[colIndex].operation(acc, next)))
|
|
.Sum();
|
|
}
|
|
|
|
private (Func<long, long, long> operation, long opBaseValue) ParseOperand(string operand) => operand switch
|
|
{
|
|
"+" => ((long a, long b) => a + b, 0),
|
|
"*" => ((long a, long b) => a * b, 1),
|
|
_ => throw new ArgumentOutOfRangeException(nameof(operand))
|
|
};
|
|
} |