public TwoSatSolver(int n, int[] vs, int[] us, bool[] vb, bool[] ub)
{
N = n;
G = new List <int> [2 * N];
for (int i = 0; i < 2 * N; i++)
{
G[i] = new List <int>();
}
for (int i = 0; i < vs.Length; i++)
{
G[vs[i] + (vb[i] ? N : 0)].Add(us[i] + (ub[i] ? 0 : N));
G[us[i] + (ub[i] ? N : 0)].Add(vs[i] + (vb[i] ? 0 : N));
}
StrongConnectedGraph Scc = new StrongConnectedGraph(G);
OK = true;
for (int i = 0; i < N; i++)
{
OK &= !Scc.SameAffilication(i, i + N);
}
}
void Calc()
{
int N = re.i();
int M = re.i();
G = new List <int> [N];
order = new List <int> [N];
revG = new List <int> [N];
revorder = new List <int> [N];
for (int j = 0; j < N; j++)
{
G[j] = new List <int>();
order[j] = new List <int>();
revG[j] = new List <int>();
revorder[j] = new List <int>();
}
for (int j = 0; j < M; j++)
{
int f = re.i() - 1;
int t = re.i() - 1;
G[f].Add(t);
revG[t].Add(f);
order[f].Add(j);
revorder[t].Add(j);
}
bool[] Changed = new bool[M];
for (int i = 0; i < N; i++)
{
int[] OK1 = new int[N];
OK1[i] = N + 5;
for (int j = 0; j < G[i].Count; j++)
{
dfs(G[i][j], j + 1, OK1);
}
int[] OK2 = new int[N];
OK2[i] = N + 5;
for (int j = G[i].Count - 1; j >= 0; j--)
{
dfs(G[i][j], j + 1, OK2);
}
for (int j = 0; j < G[i].Count; j++)
{
if (OK1[G[i][j]] != j + 1 || OK2[G[i][j]] != j + 1)
{
Changed[order[i][j]] = !Changed[order[i][j]];
}
}
}
StrongConnectedGraph Scc = new StrongConnectedGraph(G);
for (int i = 0; i < N; i++)
{
for (int j = 0; j < revG[i].Count; j++)
{
if (Scc.SameAffilication(i, revG[i][j]))
{
Changed[revorder[i][j]] = !Changed[revorder[i][j]];
}
}
}
for (int i = 0; i < M; i++)
{
if (Changed[i])
{
sb.Append("diff\n");
}
else
{
sb.Append("same\n");
}
}
}
