连通图问题 POJ 1236 Network of Schools (Tarjian缩点后建图,求出入度) UVA - 315 Network(Tarjian求无向图割点模板题) UVA-796 Critical Links(Tarjian求无向图桥,判重边) HDU 4635 Strongly connected(Tarjian强连通分量)