如果遍历整个树还没有找到,结束程序。...代码实现 //http://www.geeksforgeeks.org/breadth-first-traversal-for-a-graph/ // Program to print BFS traversal...g.addEdge(1, 2); g.addEdge(2, 0); g.addEdge(2, 3); g.addEdge(3, 3); cout Bre