public void Swap(int idx1, int idx2)
{
PermutationEnumerator <T> .ElementStatus statu = this._status[idx1];
this._status[idx1] = this._status[idx2];
this._status[idx2] = statu;
T obj = this._sequence[idx1];
this._sequence[idx1] = this._sequence[idx2];
this._sequence[idx2] = obj;
}
public bool MoveNext()
{
if (this._status == null)
{
this._status = new PermutationEnumerator <T> .ElementStatus[this._sequence.Length];
this._status[0] = new PermutationEnumerator <T> .ElementStatus(1U, new bool?());
for (uint index = 1; (long)index < (long)this._sequence.Length; ++index)
{
this._status[(int)index] = new PermutationEnumerator <T> .ElementStatus(index + 1U, new bool?(false));
}
return(true);
}
int num = 0;
PermutationEnumerator <T> .ElementStatus elementStatus1 = new PermutationEnumerator <T> .ElementStatus(0U, new bool?());
bool?nullable1;
for (int index = 0; index < this._status.Length; ++index)
{
if (elementStatus1.Value < this._status[index].Value)
{
nullable1 = this._status[index].Direction;
if (nullable1.HasValue)
{
num = index;
elementStatus1 = this._status[index];
}
}
}
nullable1 = elementStatus1.Direction;
if (!nullable1.HasValue)
{
return(false);
}
int idx1 = num;
int idx2 = elementStatus1.IsForward ? num + 1 : num - 1;
this.Swap(idx1, idx2);
if (idx2 > idx1 && idx2 < this._status.Length - 1)
{
if (this._status[idx2 + 1].Value > elementStatus1.Value)
{
PermutationEnumerator <T> .ElementStatus elementStatus2 = elementStatus1;
nullable1 = new bool?();
bool?nullable2 = nullable1;
elementStatus2.Direction = nullable2;
}
}
else if (idx2 < idx1 && idx2 > 0 && this._status[idx2 - 1].Value > elementStatus1.Value)
{
PermutationEnumerator <T> .ElementStatus elementStatus2 = elementStatus1;
nullable1 = new bool?();
bool?nullable2 = nullable1;
elementStatus2.Direction = nullable2;
}
if (idx2 == 0 || idx2 == this._status.Length - 1)
{
PermutationEnumerator <T> .ElementStatus statu = this._status[idx2];
nullable1 = new bool?();
bool?nullable2 = nullable1;
statu.Direction = nullable2;
}
for (int index = 0; index < this._status.Length; ++index)
{
if (this._status[index].Value > elementStatus1.Value)
{
this._status[index].Direction = new bool?(index < idx2);
}
}
return(true);
}