z 无向图(undirected graph) 哥尼斯堡七桥 Euler 图 无向图,简称图,是一个用线(边)连接在一起的节点(顶点)的集合。严 格地说,图是一个三元组 G=( V, E, I ), 其中,V 是顶点的集合,E 是边的集 合,而 I 是关联关系,它指明了 E 中的每条边与 V 中的每个顶点之间的关联关 系:每条边必定连接两个而且只有两个顶点,它们称为该边的端点
(1) Hole particle current from E to B (2)Electron particle current from B to E (3)Recombination current in B (4) Hole particle current originating in E and reaching C (5)Reverse electron particle current from c to B (6) Reverse hole particle current from b to c (What is difference between \current\ and\particle current ? OE F Schubert, Rensselaer Polytechnic Institute, 2003