public int FindJudge(int N, int[][] trust)
{
DiGraph di = new DiGraph(N);
for (int i = 0; i < trust.Length; i++)
{
di.AddEdge(trust[i][0] - 1, trust[i][1] - 1);
}
int ansCandidate = -1;
for (int i = 0; i < di.Count(); i++)
{
if (di.OutDeg(i) == 0)
{
if (ansCandidate == -1)
{
ansCandidate = i;
}
else
{
return(-1);
}
}
}
if (ansCandidate == -1)
{
return(-1);
}
for (int i = 0; i < di.Count(); i++)
{
bool isTrust = false;
if (i != ansCandidate)
{
foreach (var j in di.Adj(i))
{
if (j == ansCandidate)
{
isTrust = true;
break;
}
}
if (!isTrust)
{
return(-1);
}
}
}
return(ansCandidate + 1);
}
