我需要计算不同的组合：[1,2]

public void DistinctPairsTest()
{
    IList<Tuple<int,int>> pairs = new List<Tuple<int,int>>();
    pairs.Add(Tuple.Create(1,1));
    pairs.Add(Tuple.Create(1,2));
    pairs.Add(Tuple.Create(2,1));
    pairs.Add(Tuple.Create(2,1));

    IList<Tuple<int,int>> distinctPairs = GetDistinctPairs(pairs);

    Assert.AreEqual(2,distinctPairs.Count);
}

private IList<Tuple<T,T>> GetDistinctPairs<T>(IList<Tuple<T,T>> pairs)
{
    throw new NotImplementedException();
}

你将如何实现通用的GetDistinctPairs(pair)？

解：

正如Heinzi和Dennis_E所建议的那样,我实现了一个通用的IEqualityComparer.欢迎改进:-)

public class CombinationEqualityComparer<T> : IEqualityComparer<Tuple<T,T>>
{
    public bool Equals(Tuple<T,T> x,Tuple<T,T> y)
    {
        bool equals = new HashSet<T>(new[] { x.Item1,x.Item2 }).SetEquals(new[] { y.Item1,y.Item2 });
        return equals;
    }

    public int GetHashCode(Tuple<T,T> obj)
    {
        return obj.Item1.GetHashCode() + obj.Item2.GetHashCode();
    }
}