32 lines
1.0 KiB
C#
32 lines
1.0 KiB
C#
using System.Collections.Generic;
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using System.Linq;
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namespace aoc2019.lib
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{
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public static class Extensions
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{
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public static IEnumerable<IEnumerable<T>> Permute<T>(this IEnumerable<T> list)
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{
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if (list.Count() == 1) return new[] {list};
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return list.SelectMany(t => Permute(list.Where(x => !x.Equals(t))), (v, p) => p.Prepend(v));
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}
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public static IEnumerable<string> Chunk(this string str, int chunkSize)
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{
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for (var i = 0; i < str.Length; i += chunkSize)
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yield return str.Substring(i, chunkSize);
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}
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public static string ToDelimitedString<T>(this IEnumerable<T> enumerable, string delimiter = "")
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{
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return string.Join(delimiter, enumerable);
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}
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public static IEnumerable<T> Repeat<T>(this IEnumerable<T> sequence, int? count = null)
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{
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while (count == null || count-- > 0)
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foreach (var item in sequence)
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yield return item;
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}
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}
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} |