public void Solve()
{
int N = Reader.Int(), M = Reader.Int();
var E = Reader.IntTable(M);
int NQ = Reader.Int();
var Q = Reader.IntTable(NQ);
var comp = new TwoEdgeConnectedComponent(N, E, 1);
var lca = new LowestCommonAncestor(comp.Components.Count);
for (int a = 0; a < comp.Components.Count; a++)
{
foreach (int b in comp.Components[a].Edges)
{
if (a < b)
{
lca.AddEdge(a, b);
}
}
}
lca.Init(0);
var ans = new bool[NQ];
for (int i = 0; i < NQ; i++)
{
int a = comp.VtoComponentId(Q[i][0] - 1);
int b = comp.VtoComponentId(Q[i][1] - 1);
int c = comp.VtoComponentId(Q[i][2] - 1);
ans[i] = a == b && a == c || lca.Dist(a, b) + lca.Dist(b, c) == lca.Dist(a, c);
}
Console.WriteLine(string.Join("\n", ans.Select(b => b ? "OK" : "NG")));
}
public void Solve()
{
int N = Reader.Int(), A = Reader.Int() - 1, B = Reader.Int() - 1;
var E = new List <int> [2][];
for (int who = 0; who < 2; who++)
{
E[who] = new List <int> [N];
for (int i = 0; i < N; i++)
{
E[who][i] = new List <int>();
}
for (int i = 0; i < N - 1; i++)
{
int a = Reader.Int() - 1, b = Reader.Int() - 1;
E[who][a].Add(b);
E[who][b].Add(a);
}
}
var lca = new LowestCommonAncestor(B, E[1]);
var seen = new bool[N];
var que = new Queue <int>();
que.Enqueue(A);
int ans = lca.Depth(A) * 2;
for (int steps = 1; que.Count > 0; steps++)
{
var nextQue = new Queue <int>();
while (que.Count > 0)
{
int at = que.Dequeue();
foreach (int next in E[0][at])
{
if (!seen[next])
{
if (lca.Dist(at, next) > 2)
{
Console.WriteLine(-1); return;
}
seen[next] = true;
int nextDepth = lca.Depth(next);
if (nextDepth >= steps)
{
ans = Math.Max(ans, nextDepth * 2);
}
if (nextDepth > steps)
{
nextQue.Enqueue(next);
}
}
}
}
que = nextQue;
}
Console.WriteLine(ans);
}
public void Solve()
{
int N = Reader.Int();
var E = Reader.IntTable(N - 1);
int NQ = Reader.Int();
var Q = Reader.IntTable(NQ);
var g = new LowestCommonAncestor(N, E, 0, 1);
var ans = new StringBuilder();
foreach (var q in Q)
{
int a = q[0] - 1, b = q[1] - 1;
int len = 1 + g.Dist(a, b);
ans.Append(len + "\n");
}
Console.Write(ans);
}
public void Solve()
{
int N = NextInt(), M = NextInt();
var E = new int[M][];
for (int i = 0; i < M; i++)
{
E[i] = new[] { NextInt(), NextInt() }
}
;
int NQ = NextInt();
var Q = new int[NQ][];
for (int i = 0; i < NQ; i++)
{
Q[i] = new[] { NextInt(), NextInt(), NextInt() }
}
;
var comp = new TwoEdgeConnectedComponent(N, E, 1);
var lca = new LowestCommonAncestor(comp.Components.Count);
for (int a = 0; a < comp.Components.Count; a++)
{
foreach (int b in comp.Components[a].Edges)
{
if (a < b)
{
lca.AddEdge(a, b);
}
}
}
lca.Init(0);
var ans = new bool[NQ];
for (int i = 0; i < NQ; i++)
{
int a = comp.VtoComponentId(Q[i][0] - 1);
int b = comp.VtoComponentId(Q[i][1] - 1);
int c = comp.VtoComponentId(Q[i][2] - 1);
ans[i] = a == b && a == c || lca.Dist(a, b) + lca.Dist(b, c) == lca.Dist(a, c);
}
Console.WriteLine(string.Join("\n", ans.Select(b => b ? "OK" : "NG")));
}
TextReader _reader = Console.In;
int NextInt()
{
int c;
while ((c = _reader.Read()) < '0' || c > '9')
{
}
int res = c - '0';
while ((c = _reader.Read()) >= '0' && c <= '9')
{
res = res * 10 + c - '0';
}
return(res);
}
}