Sha256: f81e87cf4af24a1c02e7e3da6ed507b079fcf7873ecbaa1beed071c7f7a4f77b
Contents?: true
Size: 1.67 KB
Versions: 396
Compression:
Stored size: 1.67 KB
Contents
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
public static class RunLengthEncoding
{
public static string Encode(string input) => string.Join("", GroupConsecutive(input).Select(EncodeConsecutive));
private static string EncodeConsecutive(Tuple<char, int> group) => group.Item2 > 1 ? $"{group.Item2}{group.Item1}" : group.Item1.ToString();
private static IEnumerable<Tuple<char, int>> GroupConsecutive(string input)
{
if (input.Length == 0)
{
yield break;
}
var current = input[0];
var count = 0;
foreach (var character in input)
{
if (character == current)
{
count++;
}
else
{
yield return Tuple.Create(current, count);
current = character;
count = 1;
}
}
yield return Tuple.Create(current, count);
}
public static string Decode(string input) => string.Join("", Regex.Matches(input, @"(\d+[^\d]|[^\d])").Cast<Match>().Select(Decode));
private static string Decode(Match match)
{
if (EncodedSingleCharacter(match))
{
return match.Value;
}
return DecodeConsecutiveCharacters(match);
}
private static bool EncodedSingleCharacter(Match match) => match.Value.Length == 1;
private static string DecodeConsecutiveCharacters(Match match)
{
var character = match.Value[match.Value.Length - 1];
var count = int.Parse(match.Value.Substring(0, match.Value.Length - 1));
return new string(character, count);
}
}
Version data entries
396 entries across 396 versions & 1 rubygems