public static int[] _2Satisfiability(DirectedGraph g)
{
MetaGraph m = new MetaGraph(g);
//return m.stack.ToArray();
//m.id.Length ~ m.stack.Count
//m.id[2 * i + 1] ~ m.stack.ElementAt()
for (int i = 0; i < m.id.Length / 2; i++)
//for (int i = 0; i < m.stack.Count / 2; i++)
{
// if not solving
if (m.id[2 * i] == m.id[2 * i + 1])
//if (m.stack.ElementAt(2 * i) == m.stack.ElementAt(2 * i + 1))
{
return(new int[1] {
0
});
}
}
int[] res = new int[m.id.Length / 2 + 1];
//int[] res = new int[m.stack.Count / 2 + 1];
res[0] = 1;
// see Algorithms by Dasgupta, Papadimitriou, Vazirani. McGraw-Hill. 2006, page 102, task 3.28
for (int i = m.id.Length; i > 0; i--)
//for (int i = m.stack.Count; i > 0; i--)
{
for (int v = 0; v < m.id.Length; v++)
//for (int v = 0; v < m.stack.Count; v++)
{
if (m.id[v] != i)
//if (m.stack.ElementAt(v) != i)
{
continue;
}
if (res[v / 2 + 1] != 0)
{
continue;
}
int r;
if (v % 2 == 0)
{
r = (v + 2) / (+2);
}
else
{
r = (v + 1) / (-2);
}
res[v / 2 + 1] = r;
}
}
return(res);
}
public static int[] _2Satisfiability(DirectedGraph g)
{
MetaGraph m = new MetaGraph(g);
//return m.stack.ToArray();
//m.id.Length ~ m.stack.Count
//m.id[2 * i + 1] ~ m.stack.ElementAt()
for (int i = 0; i < m.id.Length / 2; i++)
//for (int i = 0; i < m.stack.Count / 2; i++)
{
// if not solving
if (m.id[2 * i] == m.id[2 * i + 1])
//if (m.stack.ElementAt(2 * i) == m.stack.ElementAt(2 * i + 1))
{
return new int[1] { 0 };
}
}
int[] res = new int[m.id.Length / 2 + 1];
//int[] res = new int[m.stack.Count / 2 + 1];
res[0] = 1;
// see Algorithms by Dasgupta, Papadimitriou, Vazirani. McGraw-Hill. 2006, page 102, task 3.28
for (int i = m.id.Length; i > 0; i--)
//for (int i = m.stack.Count; i > 0; i--)
{
for (int v = 0; v < m.id.Length; v++)
//for (int v = 0; v < m.stack.Count; v++)
{
if (m.id[v] != i)
//if (m.stack.ElementAt(v) != i)
{
continue;
}
if (res[v / 2 + 1] != 0)
{
continue;
}
int r;
if (v % 2 == 0)
{
r = (v + 2) / (+2);
}
else
{
r = (v + 1) / (-2);
}
res[v / 2 + 1] = r;
}
}
return res;
}