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@talecrafter
Created November 17, 2015 08:56
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using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public static class ListExtensions
{
public static T PickRandom<T>(this IList<T> source)
{
if (source.Count == 0)
return default(T);
int i = Random.Range(0, source.Count);
return source[i];
}
public static T PopRandom<T>(this IList<T> source)
{
if (source.Count == 0)
return default(T);
int i = Random.Range(0, source.Count);
T value = source[i];
source.RemoveAt(i);
return value;
}
public static T First<T>(this IList<T> source)
{
if (source.Count == 0)
return default(T);
return source[0];
}
public static T Last<T>(this IList<T> source)
{
if (source.Count == 0)
return default(T);
return source[source.Count - 1];
}
public static T PopFirst<T>(this IList<T> source)
{
if (source.Count == 0)
return default(T);
T value = source.First();
source.RemoveAt(0);
return value;
}
public static T PopLast<T>(this IList<T> source)
{
if (source.Count == 0)
return default(T);
T value = source.Last();
source.RemoveAt(source.Count - 1);
return value;
}
public static T Pop<T>(this IList<T> source, int index)
{
if (source.Count <= index)
return default(T);
T value = source[index];
source.RemoveAt(index);
return value;
}
public static List<T> Clone<T>(this List<T> source)
{
return new List<T>(source);
}
public static void Shuffle<T>(this IList<T> list)
{
int index = list.Count;
while (index > 1)
{
index--;
int newPos = Random.Range(0, index + 1);
T temp = list[newPos];
list[newPos] = list[index];
list[index] = temp;
}
}
public static void SwitchPlaces<T>(this IList<T> list, int indexOne, int indexTwo)
{
if (indexOne < 0 || indexTwo < 0 || indexOne == indexTwo || indexOne >= list.Count || indexTwo >= list.Count)
return;
T temp = list[indexOne];
list[indexOne] = list[indexTwo];
list[indexTwo] = temp;
}
}
@dotsquid
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dotsquid commented Sep 1, 2016

During the shuffling of the list you can iterate only the half of it, since after the swap two elements are repositioned ;)

@talecrafter
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Author

If the Shuffling would stop halfway, we cannot be sure the first indices have been moved.
https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle

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