using System;
using System.Collections.Generic;
namespace HeuristicLab.Algorithms.GraphRouting {
  public class Pair<T> {
    public T First { get; private set; }
    public T Second { get; private set; }

    public Pair(T first, T second) {
      First = first;
      Second = second;
    }

    public override int GetHashCode() {
      return First.GetHashCode() ^ Second.GetHashCode();
    }

    public override bool Equals(object other) {
      Pair<T> pair = other as Pair<T>;
      if (pair == null) {
        return false;
      }
      return (this.First.Equals(pair.First) && this.Second.Equals(pair.Second));
    }
  }

  class PairComparer<T> : IComparer<Pair<T>> where T : IComparable {
    public int Compare(Pair<T> x, Pair<T> y) {
      if (x.First.CompareTo(y.First) < 0) {
        return -1;
      } else if (x.First.CompareTo(y.First) > 0) {
        return 1;
      } else {
        return x.Second.CompareTo(y.Second);
      }
    }
  }
}